bluuebunny/crossref_metadata_2025 huggingface dataset:
Service load analysis of unbonded partially prestressed concrete members
Authors: Au F. T. K. , Du J. S. , Cheung Y. K.
Published: October 2009

In the design of unbonded partially prestressed concrete (UPPC) members, it is necessary to estimate the stresses in steel and concrete in order to satisfy the requirements of the serviceability limit state. A numerical method has been developed to predict the response of UPPC beams under service load, and the results agree well with experimental results reported in the technical literature. A parametric study has been undertaken to evaluate the variation of stress in prestressed steel under service load as well as the ratio of length of equivalent deformation region to the neutral axis depth at critical section. Results show that this ratio is not sensitive to the variation of the combined reinforcement index. From the moment of application of load to the cracking of the beam, and until the yielding of non-prestressed steel, this ratio is fairly stable and it can be taken as a constant. With the determination of this ratio, an approximate cubic equation similar to that used for cracked section analysis of bonded partially prestressed members is established. Predictions of stresses under service load are in good agreement with available test data.
Seismic performance of high-strength concrete columns
Authors: Hwang S.-K. , Yun H.-D. , Park W.-S. , Han B.-C.
Published: October 2009

This experimental investigation was conducted to examine the behaviour of eight one-third scale columns made of high-strength concrete. The columns were subjected to a constant axial load corresponding to 30% of the column axial load capacity and a cyclic horizontal load-inducing reversed bending moment. The variables studied in this research are the volumetric ratio of transverse reinforcement (ρs = 1·58, 2·25%), tie configuration (Type H, Type C, Type D) and tie yield strength (fyh = 548·8 and 779·1 MPa). Test results show that the flexural strength of all the columns exceeds calculated flexural capacities based on the equivalent concrete stress block used in the current design code. Columns with 42% higher amounts of transverse reinforcement than that required by seismic provisions of ACI 318-02 showed ductile behaviour. With an axial load of 3% of the axial load capacity, it is recommended that the yield strength of transverse reinforcement be held equal to or below 548·8 MPa. Relationships between the calculated damage index and the observed damage such as initial crack, spalling of concrete, buckling of longitudinal bar, and crushing of concrete are proposed.
Adhesion of repair systems to concrete: influence of interfacial topography and transport phenomena
Authors: Courard L.
Published: October 2009

Eight types of cement slurries were applied to concrete substrates. Surface preparation involved mechanical action – sandblasting and polishing – as well as saturation regulation, both dry and saturated surface wet. The adhesion strength for the different combinations was measured by direct tensile tests. Multivariate statistical analysis led to the identification of a major effect of surface saturation on the results. Knowledge of the interfacial behaviour was obtained by the discrimination of the effects of partial interaction between slurry and aggregates and slurry and cement mortar, respectively. It clearly showed that a third factor has to be taken into account in the explanation of adhesion, namely the interfacial transition zone between cement paste and aggregates, due to its porosity and anchoring effect. This effect was quantified by topographical observation and image analysis. Penetration of cement slurry was also confirmed by observation with binocular and fluorescent microscopy.
Yield line theory and concrete plasticity
Authors: Braestrup M. W.
Published: October 2009

This paper reviews the relationship between yield line theory, developed for reinforced concrete slabs by Johansen in the 1930s and 1940s, and limit analysis, formulated by the Hodge–Hill–Prager school around 1950. Recalling work from the 1970s, it is shown that not only is yield line theory fully compatible with limit analysis, but the Johansen ‘stepped’ yield criterion is in fact the only yield condition for the slab that allows coinciding upper and lower bounds in the sense of limit analysis to be derived by yield line theory. The yield condition for an arbitrarily reinforced slab is reproduced in closed form, obviating the need for coordinate transformations, and allowing the permissibility of stress states to be checked for anisotropic slabs with non-coinciding principal directions of top and bottom reinforcement.
Concrete plasticity in structural design practice
Authors: Gurley C.
Published: October 2009

This paper presents a view of the state of concrete plasticity as seen by a retired consulting engineer/structural designer. The author discovered the ‘bimoment’ method for the design of torsion-free Hillerborg slabs using upper bound collapse mechanism methods. He has also provided collapse mechanisms for plane-stress problems including shear in ordinary beams where longitudinal and transverse reinforcement may both be yielding.
Cracking due to drying shrinkage in an RC wall. Part 1: estimation by bond analysis
Authors: Seo T. , Ohno Y. , Choi C.
Published: October 2009

Cracks owing to drying shrinkage in reinforced concrete (RC) walls are affected by the reinforcement ratio, the diameter of reinforcing steel, the concrete strength, the shrinkage of concrete, the creep of concrete, the restraint ratio and the length of member. However, because there is no established estimation method that can consider all these parameters, a quantitative crack control of an RC wall is impossible. Accordingly, in this paper, to estimate drying shrinkage cracking behaviour in the walls of RC buildings, an analytical method based on bond analysis was proposed. To verify the validity of the method of analysis of crack width and number of cracks, the uniaxial restrained shrinkage cracking specimen and the small-scale RC wall model were made, and the strains of reinforcing steel and concrete, the crack width and the number of cracks were measured. As a result, generally good agreements were shown between the analytical values and the experimental values.
Cracking due to drying shrinkage in an RC wall. Part 2: Proposal of estimation equation
Authors: Seo T. , Ohno Y. , Choi C.
Published: October 2009

The analysis method based on the bond analysis was proposed to estimate cracking behaviour resulting from drying shrinkage of a reinforced concrete (RC) wall, and the validity of this method was verified from experimental study. However, there is a shortcoming because the calculation is complex and a simple estimation method is needed. Accordingly, for the estimation of the drying shrinkage cracking (crack width, number of cracks) and the quantitative crack control design of an RC wall in the buildings, improved and simple equations based on the bond analysis were proposed in this paper, and the calculation values were compared with the experimental values and investigation values by the field study.
Estimating the size composition of sediment surfaces through image analysis
Authors: McEwan I. K. , Sheen T. M. , Cunningham G. J. , Allen A. R.
Published: October 2009

This paper describes a technique to extract grain size information from areal images of sediment surfaces. An edge-detection algorithm is used to obtain the particle boundaries and segment the image into individual grains. Further processing of the segmented image can result in detailed information about grain size, position, orientation and, depending on the type of image, exposure. The images analysed in this paper were obtained by laser altimeter scans of sediment surfaces in laboratory conditions. Further development of the method could harness photo-grammetric methods which are currently under development as a means of obtaining suitable images. Alternatively, carefully lit photographs have the potential to provide sufficient contrast at grain edges for the successful implementation of the image-processing technique. Therefore, this paper can be regarded as an interim step towards the provision of an improved method for estimating surface sizes and composition. The results presented are sufficiently encouraging to make field trials, probably with other image types, an attractive possibility.
Initial motion of streambeds composed of coarse uniform sediments
Authors: Shvidchenko A. B. , Pender G.
Published: October 2009

Results of an experimental study of the initial motion of coarse uniform sediments are presented in this paper. The experiments were conducted in an 8 m long, 0·3 m wide by 0·3 m deep tilting flume. Natural sediments were used and they ranged in size from 1 mm to 14 mm. The purpose of the experiments was to determine flow conditions associated with the initiation of bed sediment motion. To eliminate the subjectivity in defining the beginning of streambed movement, the concept of critical-bed state is linked to the intensity of sediment motion. The experiments reveal that critical-bed shear-stress for sediment motion depends not only on the grain size, but also on the bed slope. The latter fact is explained by the effect of relative depth (depth to grain-size ratio) on overall flow resistance. It is also shown that the value of critical dimensionless bed shear-stress is not constant for rough turbulent flow, as is usually assumed. The same conclusion follows from the measurements of turbulence characteristics near the surface of the bed. A revised Shields diagram relating critical stress, grain Reynolds number and bed slope is derived for different intensities of sediment motion. Finally, a diagram relating critical flow depth, bed slope and grain size is presented in a form suitable for use by design engineers.
Resistance and boundary shear in circular conduits with flat beds running part full
Authors: Sterling M. , Knight D. W.
Published: October 2009

This paper presents experimental results concerned with the overall resistance and boundary shear in circular conduits flowing part full, with and without a flat bed, simulating a hydropower tunnel or deposited sediments in a sewer. The importance of flow resistance in determining the stage–discharge curve is examined in detail. This paper illustrates that Manning's n is invariant with stage and, as a consequence, an empirical relationship based on Manning's formula can be established which allows the prediction of a non-dimensional stage–discharge curve. When the conduit is running part full, there is strong evidence of secondary flows being present, based on distortions in the isovel patterns and in the lateral distributions of boundary shear stress. The overall frictional resistance is shown to be larger for subcritical flow than for supercritical flow over the range of Reynolds numbers tested.
Engineering feasibility studies for a large reservoir in the Fens
Authors: de Lande Long P. G. , Scott C. W.
Published: October 2009

Feltwell reservoir is a potential strategic water resource for the whole of East Anglia. This paper describes the work undertaken by Binnie Black & Veatch on the technical aspects of the site identification, pre-feasibility and feasibility studies for the construction of a reservoir at Feltwell. The process by which the site was identified is described. The incremental approach to the assessment of the feasibility of developing a reservoir at the site involving a desk study, preliminary ground investigation, pre-feasibility study and feasibility study is outlined. The bulk of the paper discusses the feasibility study undertaken in 1997/98. A feasibility ground investigation was carried out and a digital geological model was developed. This geological model was used to assess the optimum reservoir depth and capacity and to determine the embankment alignment. The problems associated with the site geology are discussed, particularly in relation to the peat covering the site and the sourcing of material for filters and drains. The selection of cut-off options and the dewatering requirements are described. The complex hydraulics of the inlet/ outlet system are also described together with the proposed solution.
Wall pressure field in the reattaching flow past deflectors—Part 2: with air injection
Authors: Narayanan R. , Manafpour M. , Kavianpour R.
Published: October 2009

Experiments have been carried out to study the effect of air injection on the wall pressures in the near field of deflectors placed in a duct. Various quantities of air have been injected just downstream of the ramps to form stationary air cavities. The variation of the cavity length has been studied as a function of the ratio of the volume of airflow to the water discharge. The wall pressure field in terms of the mean and fluctuating parts is presented. This study shows how air injection affects the wall pressure field from that without air injection. Information concerning wall pressures is expected to be useful in the design of deflectors in tunnels and spillways.
The influence of planform on flow resistance in mobile bed compound channels
Authors: Lyness J. F. , Myers W. R. C. , Cassells J. B. C. , O'Sullivan J. J.
Published: October 2009

A large-scale test facility, the United Kingdom Flood Channel Facility, has been used to compare observations of a range of overbank flows in straight compound channels and meandering compound channels with similar geometries, floodplain roughnesses and mobile main channel bed material. For straight and meandering channels with smooth floodplains, the single channel Manning's n values were similar, but single channel Manning's n values for the meandering channel with roughened floodplains are approximately 50% greater than those for the straight channel with similarly roughened floodplains. At higher relative depths, Yr > 0·25, the floodplain Manning's n values become similar for both the straight and meandering channels indicating that most of the overbank flow for the meandering channel is in the valley direction at these depths. The meandering main channel with roughened floodplains was found to have the largest mobile bed features.
Water in rivers: flooding
Authors: White W. R.
Published: October 2009

This paper gives a brief introduction to one aspect of the subject of water in rivers. It is concerned mainly with recent experience in river basin management and in flood mitigation. Brief mention is made of the problems of sediment movement through river systems. It provides a basis for developing a ‘vision’ for how we view flooding and flood protection and how we should deal with flooding problems. The paper has been revised and updated in the light of international discussions which were coordinated through the International Association of Hydraulic Engineering and Research. The main factors which need to be considered regarding river flooding include technical, social and political aspects as follows the importance of all parties understanding the issues, including acknowledgement that absolute security from flooding is neither technically possible (or even desirable) nor economically justifiable flood forecasting technologies flood warning procedures and responsibilities flood protection including consideration of structural and non-structural methods the acceptance of procedures and designs which are based on a sound analysis of risk the importance of good communications before, during and after flood events the desire to create sustainable conditions for future generations environmental implications of flood defences in the broadest sense establishing appropriate institutional arrangements and policies for flood management integrated planning over the river basin.
Effect of tailwater depth and model scale on scour at culvert outlets
Authors: Day R. A. , Liriano S. L. , White W. R.
Published: October 2009

The results from an experimental programme investigating the effect of tailwater depth and model scale on scour depths downstream of culverts are shown. Results are presented for cohesionless uniform sands and gravels. A model for predicting equilibrium scour depth and incorporating a correction function to take account of tailwater depth is shown to provide good agreement with previously published work. It is shown that the model scale does have an impact on the reliability with which scour hole data can be presented, in particular those experiments in which Reynolds number falls below 4 × 103.
Human health risk-based design of ocean outfalls
Authors: Mukhtasor  , Husain T. , Lye L. M. , Sharp J. J.
Published: October 2009

In recent years there has been a trend towards specifying water quality guidelines from an epidemiological viewpoint. This raises the possibility that ocean outfall design could itself be looked at from the point of view of the risk to human health from exposure to specific pollutants. An approach to health risk-based design of ocean outfalls is presented in this paper. The approach is based on an integration of the principles of human health risk assessment and ocean outfall design. Hazard identification of rota-virus—used as an example of a typical pathogen in sewage—and dose–response relationships are reviewed. An empirical initial dilution model is combined with secondary dilution and decay models to quantify virus exposures during swimming. The health risk to a swimmer at a specified distance from the outfall discharge is then evaluated by integrating the exposure and dose–response models. Risk of infection, clinical illness, and mortality are all evaluated with a case study using data from an existing outfall. The applicability of the approach to ocean outfall design is presented by quantifying the risks of using a public beach for swimming for a given outfall design scenario. Different scenarios are used to simulate the risk of infection, clinical illness, and mortality, from which the location of the designed outfall may be determined to better assure the safety of swimming areas. A probabilistic analysis is presented to investigate the uncertainty in estimated health risk from potential design scenarios.
Cardiff Bay Barrage
Authors: Crompton D.
Published: October 2009

Cardiff Bay Barrage is one of the key elements in the urban regeneration of South Cardiff. This paper outlines the need for that regeneration and takes an overview of the barrage project. It considers the legislative process and the economic considerations that were necessary before the £120m structure could be constructed. Environmental considerations were important. The effect of the barrage on over-wintering wading birds and the loss of a Site of Special Scientific Interest had to be mitigated, a £10m fresh water habitat was constructed. Groundwater rise within the City of Cardiff consequent on construction of the barrage was reduced by provision of a dewatering system and a system of surveys on 25 000 properties ensure that any possible damage due to groundwater rise is identified and can be rectified. Water quality issues including oxygenation of the bay are considered. The barrage design is outlined as an introduction to subsequent papers. The contractual issues are discussed, the out-turn cost was only 5% above the estimated out-turn cost when the project commenced on site. The development outputs predicted when the project was under consideration have been achieved and the economic return on the project shows a pay back period of less than 2 years
Environmental regulation of the Cardiff Bay Barrage
Authors: Andrews D. , Gulson J.
Published: October 2009

This paper describes the environmental regulation of Cardiff Bay by the Environment Agency (and its predecessors) from the early planning of the barrage to February 2002. Temporary impoundment took place in November 1999, with the bay being filled with seawater and occasionally emptied. Permanent impoundment with fresh water was achieved by April 2000. The framework for regulation was established by the Cardiff Bay Barrage Act 1993, which authorised the construction of a barrage across Cardiff Bay to impound the rivers Taff and Ely. Since impoundment, the water environment has required careful and balanced management to take into account the sometimes conflicting needs of water quality, fisheries, flood defence, recreation and business. The Agency has played a key role in ensuring that such management takes place without compromising environmental standards.
Wave-induced nearshore currents at a tri-cuspate beach in the UKCRF
Authors: Borthwick A. G. L. , Foote Y. L. M.
Published: October 2009

This paper describes an investigation into the surf-zone hydrodynamics at a fixed tri-cuspate beach installed in the UK Coastal Research Facility (UKCRF). Measurements are presented of the wave height field, horizontal wave-induced current patterns and detailed structure of rip and meandering longshore currents. For waves normal to the beach, the flow patterns consist of repeated primary circulation cells driven by longshore currents feeding into seaward rip currents. Each rip current is a narrow time-varying jet. From the measurements, the rip currents reached a maximum non-dimensional speed of [Formula: see text] (below the threshold of a stopping current), where |V| is the magnitude of current velocity, g is acceleration due to gravity and h is still water depth. The vertical profile through a typical rip current is reasonably uniform above a thin wave-induced oscillatory boundary layer, indicating that the rip current is predominantly a two-dimensional flow feature. Within the surf-zone, peak seaward-directed velocities occur at the top of the bed boundary layer, and incorporate the undertow in addition to the rip current. For oblique regular waves, a stable meandering longshore current forms, of magnitude above 0·5 m/s (corresponding to [Formula: see text], with a current-induced logarithmic near-bed profile. The data should be useful in validating numerical models of nearshore wave–current interaction.
Critical depth prediction in straight compound channels
Authors: Lee P. J. , Lambert M. F. , Simpson A. R.
Published: October 2009

Critical depth is the depth at which the flow in an open conduit undergoes a transition from subcritical to supercritical regimes. The prediction of critical depth in a prismatic channel can be achieved to a high degree of accuracy. This is not the case for two-stage channels (main channel with flanking floodplain), also commonly known as compound channels. Traditionally, critical depth is predicted based on minimum specific energy, and this paper investigates the validity of this and several other methods of critical depth prediction for compound channels. It has been found that flow in compound channels does not undergo a sharp critical flow transition as occurs in prismatic channels. Instead, the change between fully subcritical and fully supercritical occurs over a depth range, whereby different regions in the cross-section maybe either sub- or supercritical. This has been termed a ‘mixed-flow’ region. It has been found that the point of minimum specific energy does not coincide with either the beginning or the end of this mixed flow transition, rendering such predictions ineffectual. A new method for determining critical depth in a compound channel is presented and compared with other prediction techniques. Methods of incorporating the effects of the momentum interaction have been used to improve the prediction of the velocity profile within the channel and locate the mixed flow transition zone.
Analytical solution of a flood wave resulting from dike failure
Authors: Sarma A. K. , Das M. M.
Published: October 2009

The occurrence of floods due to failures of river dikes is becoming a major problem for many developing countries. Prior knowledge of flood movement acquired through model simulation can help the planner in formulating an efficient management scheme. Numerical schemes for flow simulation are gaining popularity in this context. However, the implementation of a numerical scheme in this situation generally calls for analytic computation of an initial water surface profile. Several analytical methods with various degrees of sophistication are available for solving the dam break problem. However, an appropriate method of solution is not available for the situation of a dike breach flood where the released water moves in a lateral direction relative to the main stream. Therefore a new characteristic-based analytical solution of flood propagation has been developed for the situation where flood water, being released through an opening in the river dike, moves two-dimensionally over a valley.
Numerical simulation of graded sediment transport
Authors: Mikoš M. , Pender G. , Hoey T. , Shvidchenko A. , Petkovšek G.
Published: October 2009

River engineers commonly need to predict sediment transport rates in the absence of adequate field data, and so make frequent use of numerical sediment transport models. This paper compares the performance of two such computer models for the prediction of graded sediment transport. The intention is to inform model users of the level of accuracy that can be expected for typical applications. One model uses the Parker bedload transport equation and the other uses the Meyer-Peter and Müller sediment transport formula modified for use with graded sediments. The computer model predictions are compared with detailed experimental data collected for the purpose of computer model validation. The Meyer-Peter and Müller-based model produces better predictions of sediment transport rates, whereas the Parker-based model performs better in terms of the grain sizes of both the bedload and the bed material. These results illustrate the limitations of present models and indicate areas requiring further investigation.
Swabi salinity control and reclamation project
Authors: Donaldson M. , Bangash H. D. , Stacey D. B.
Published: October 2009

At the beginning of the last century, in the tribal territory of India's North West Frontier Province, British engineers constructed the Upper Swat Canal system. The project comprised diversion works on the River Swat to provide 2400 cusec (68 m3/s) via a canal network to irrigate over 300 000 acres (121 400 ha) of fertile rainfed land. The civil engineering is bold and imaginative, incorporating tunnels, multi-span aqueducts in stone masonry, steel siphons under major river gorges and notch fall structures, all superb examples of the engineering excellence of that era. This paper describes the rehabilitation and upgrading of the system which was carried out by the Government of Pakistan between 1991 and 1999 under a US$162 million project, funded by the Asian Development Bank.
Urban flood modelling using computational fluid dynamics
Authors: Haider S. , Paquier A. , Morel R. , Champagne J.-Y.
Published: October 2009

The paper discusses the use of a code solving two-dimensional (2D) shallow-water equations in an urban area. Two application examples are described: a laboratory model representing low-density housing, and the city of Nîmes (France), which suffered a catastrophic flood in October 1988. From these examples, the paper shows that such 2D models can provide general flow dynamics. Moreover, they can integrate description of some details (such as obstacles and storage areas), which can contribute to an understanding of some flow features and thus provide accurate results locally. For engineering use, the limits are computational time and number of cells: the two examples described show that a grid adapted to urban topography features is a way to reduce these disadvantages while providing reliable results with a convenient numerical stability, even if the size of the cells varies considerably.
Oblique rectangular sharp-crested weir
Authors: Borghei S. M. , Vatannia Z. , Ghodsian M. , Jalili M. R.
Published: October 2009

Among discharge flowmeters, the rectangular sharp-crested weir is one of the most popular and accurate, as well as being easy to work with. Using the standard weir, with the help of the conventional weir equation and Rehbock's or a similar standard formula for the discharge coefficient (Cd), the flow can be easily calculated. In order to increase the efficiency of the weir, it can be placed obliquely to the flow, increasing the effective weir length (L) and, hence, increasing the discharge for the same water head with the same channel width (B). The results of a comprehensive set of tests for oblique weirs (1·14 ≤ L/B ≤ 2·26 or oblique angles from 29° to 64°) show that for L/B less than 1·41 (oblique angles < 45°), Cd increases with increasing head but the rate slows down as L/B increases. However, for L/B greater than 1·41 (oblique angles > 45°), Cd decreases with increasing head and is constant for all values of water head while L/B = 1·41 (oblique angle = 45°). On the whole, since with oblique weirs the effective length of the weir is extended, the efficiency of the weir is also increased. Additionally, this kind of weir is aerated automatically and therefore does not need aeration. Also similar tests have been carried out for submerged flow. Finally, a single formula for discharge coefficient relating all tested oblique angles in a free flow situation has been introduced and correction coefficients for submerged flow have been suggested.
Modelling of meandering channels for overbank flow
Authors: Spooner J. , Shiono K.
Published: October 2009

The depth-averaged equation of motion in the stream-wise direction with curvilinear coordinates was considered. Its application to a meandering channel for over-bank flow was investigated using velocity and boundary shear stress. The velocity and boundary shear stress were measured using a laser Doppler anemometer and Preston tube respectively. The advection and bed friction terms in the equation of motion were found to be significant, but the transverse turbulence was found to be insignificant at the apex section. As a result the equation of motion was considerably simplified. The calibrating advection term with the data gave two equations. These gave a good prediction of velocity across the apex section for different scales of meandering channels. The investigation of the advection term with varying scaled flume data suggested that it is important for a small flume, but tends to be less significant in a large flume.
A methodology for national-scale flood risk assessment
Authors: Hall J. W. , Dawson R. J. , Sayers P. B. , Rosu C. , Chatterton J. B. , Deakin R.
Published: October 2009

Risk analysis provides a rational basis for flood management decision-making at a national scale, as well as regionally and locally. National-scale flood risk assessment can provide consistent information to support the development of flood management policy, allocation of resources and monitoring of the performance of flood mitigation activities. However, national-scale risk assessment presents particular challenges in terms of data acquisition and manipulation, numerical computation and presentation of results. A methodology that addresses these difficulties through appropriate approximations has been developed and applied in England and Wales. The methodology represents the processes of fluvial and coastal flooding over linear flood defence systems in sufficient detail to test alternative policy options for investment in flood management. Flood outlines and depths are generated, in the absence of a consistent national topographic and water level data set, using a rapid parametric inundation routine. Potential economic and social impacts of flooding are assessed using national databases of flood-plain properties and demography. A case study of the river Parrett catchment and adjoining sea defences in Bridgwater Bay in England demonstrates the application of the method and presentation of results in a geographical information system.
Integrated modelling of urban watercourses
Authors: Crabtree R. W. , Dempsey P. , Clifforde I. T. , Quinn S. , Henderson B. , Wilson A.
Published: October 2009

The paper describes an integrated modelling study that was undertaken as part of the investigations into improving the performance of the urban wastewater system of Belfast, Northern Ireland. The objective of the study was to assess the impact of the combined sewer overflow (CSO) discharges from the current and proposed upgraded sewer system on the major receiving water-courses in the Belfast urban area. The study employed the methodology of the Urban Pollution Management Manual, 2nd edition, implemented through simplified integrated urban wastewater modelling tools to assess the impacts of the CSO discharges on both inland and tidal receiving waters. The Blackstaff River is predicted to achieve its long-term water quality objective if the proposed sewerage upgrading scheme is implemented and the quality of the upstream tributaries is improved. The proposed sewer upgrading will cause a significant improvement in dissolved oxygen levels throughout the Lagan impoundment. This should allow the impoundment to achieve its environmental quality objectives. The overall study concluded that the proposed sewer upgrading scheme will allow the long-term environmental objectives for both the Blackstaff and the Lagan to be achieved, provided improvements to other sources of pollution are also addressed. The study demonstrated that the methodology employed is suitable for the investigation of large and complex systems where limited data are available.
On establishing uniform channel flow with tail gate
Authors: Yen B. C.
Published: October 2009

Steady uniform flow is a basic reference condition for hydraulic analyses of water surface profiles, resistance, velocity and pressure distributions, and channel geometry effects for open-channel flows. In laboratory experiments uniform flow is often generated by adjusting tail and entrance gates such that the flow depth remains constant along the channel. This note shows that the constant depth criterion is necessary, but insufficient, to obtain a true uniform flow for which cross-sectional flow velocity and stress distributions should also remain unchanged for a short reach around the measurement section.
Simulation of the great flood of December 1870 in Rome
Authors: Calenda G. , Calvani L. , Mancini C. P.
Published: October 2009

The inundation of the town of Rome during the great Tiber River flood of December 1870 is simulated by a depth-integrated two-dimensional varied flow model, using a constant inflow equal to the peak discharge of the flood. The model fits satisfactorily to the observed water elevations, both in the river and in the flooded areas. The development of the model is an important step in a research programme aimed at the reconstruction of the stage–discharge relationship of the Ripetta gauge in the nineteenth century, before that extensive work, undertaken in order to protect Rome from inundation, led to the present configuration of the riverbed. The use of the model allows some further insight into the behaviour of the flood in the flooded areas of the town. As an example, the peak river levels of the greatest historical flood, that of 1598, were used to simulate the flow, resulting in an estimated peak discharge of 4070 m3/s.
Performance of sandbags for domestic flood defence
Authors: Reeve D. , Badr A.
Published: October 2009

The final line of defence against flooding lies with the property itself. Deploying effective domestic flood defence systems can mitigate the devastating effects of flooding. Traditionally, householders have relied upon the use of sandbags. The Environment Agency's and local authorities’ emergency response is strongly dependent on the use of sandbags. Nonetheless, there is very little published about the performance of sandbags as a domestic flood defence. This paper presents the results of experimental research carried out to assess the performance of sandbags as a domestic flood defence. The performance criteria included water leakage, structural integrity, ease of use and environmental impact. It is concluded that sandbags have only modest performance as a domestic flood defence. The results showed that leakage from sandbags increased rapidly with increase of the outside water level. A simple analytical analysis suggests that a sandbagged doorway behaves in a manner akin to a sharp-crested triangular weir. However, the efficiency of sandbags was dependent on the number of rows and the duration of the flood.
Water resources and food security: a Caribbean case study
Authors: Shrivastava G. S.
Published: October 2009

Domestic and industrial water demands have been the dominant factors in the management of the water resources in Trinidad, and its irrigation demand has been masked by the virtual water embedded in grain imports, made possible by a vibrant economy underpinned by oil and gas. This has led to an illusion of food security. Moreover, considering the island's ample land and water resources, its dependence on imported grain is unfortunate, since rice and corn can be grown locally. This neglect of agriculture, which has historical roots, is evident by about 37% of the arable land being unused and less than 2% of arable land being under irrigation. Against this background, the island's oil and gas reserves are expected to be depleted, at current rates of production, in about 10 and 60 years respectively. These possibilities raise concerns about the sustainability of grain imports and food security on the island. This technical note briefly examines these issues and shows that it should be possible for the island to achieve a large measure of food sufficiency, provided the issue of virtual water is addressed in the island's water resources planning.
Hormesis as a Pro-Healthy Aging Intervention in Human Beings?
Authors: Marques Francine Z. , Markus M. Andrea , Morris Brian J.
Published: October 2009

Hormesis is a phenomenon in which adaptive responses to low doses of otherwise harmful factors (also called mild stressors) make cells and organisms more robust. Aging is a complex and poorly understood process. This review explores the positive effects of hormesis on aging in animal models and human cell cultures, and discusses whether it might apply to humans. As an example, repeated mild heat stress confers anti-aging benefits to normal human cells in culture. Calorie restriction and xenohormetic compounds such as resveratrol, in large part via activation of sirtuins, decrease risk of common age-related conditions, such as cancer, cardiovascular disease, type 2 diabetes, and neurological diseases, so lengthening lifespan. Mild stressors and xenohormetic dietary components have diverse molecular targets and affect many pathways. Despite experimental advances in aging research, findings in humans are still quite limited. Moderate-intensity exercise, weight management and healthy diet ameliorate diseases of aging to increase lifespan and this could involve hormesis.
Fostering Learning and Sustained Improvement: The Influence of Principalship
Authors: Møller Jorunn , Vedøy Gunn , Presthus Anne Marie , Skedsmo Guri
Published: October 2009

This article reports on selected findings from the project ‘Revisiting Successful Principals’. The authors revisited some of the schools which participated in the International Successful School Principalship Project (ISSPP) five years ago. In this article they focus on how the principals are positioning themselves as leaders, and how they are involved in the construction of a public self, while responding to questions about fostering learning and sustained improvement. The study confirms that a principal may have a significant influence on a school's policy and in particular the preferred strategies. In addition, the study revealed that, despite the new expectations which are raised towards schools in society, there was also extensive continuity at the local school.
Hard and Soft Governance: The Journey from Transnational Agencies to School Leadership
Authors: Moos Lejf
Published: October 2009

The governance and leadership at transnational, national and school level seem to be converging into a number of isomorphic forms as we see a tendency towards substituting ‘hard’ forms of governance, that are legally binding, with ‘soft’ forms based on persuasion and advice. This article analyses and discusses governance forms at several levels. The first layer is the global: the methods of ‘soft governance’ that are being utilised by transnational agencies. The second layer is the national and local: the shift in national and local governance seen in many countries, but here demonstrated in the case of Denmark, and finally the third layer: the leadership used in Danish schools. The use of ‘soft governance’ is shifting the focus of governance and leadership from decisions towards influence and power and thus shifting the focus of the processes from the decision-making itself towards more focus on the premises for decision-making, and towards the follow-up on decision-making, the connecting phase because influence is exerted in all phases. From this new perspective we are interested in analysing new forms of influences like discourses and new social technologies. In order to get an overview and further the understanding of relations and the coherence of processes of influence/power/governance, the article introduces a communications model of decision-making processes as processes of influence.
Magnetic cluster developement in In1−x
MnxSb semiconductor alloys
Authors: Rednic Lidia , Deac Iosif , Dorolti Eugen , Coldea Marin , Rednic Vasile , Neumann Manfred
Published: October 2009

X-ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), Transmission Electron Microscopy (TEM) and magnetic measurements as a function of applied magnetic field and temperature for In1−x
MnxSb (0.05≤x≤0.2) system are reported. Magnetic measurements performed at high and small magnetic field in ZFC and FC indicate the coexistence of ferromagnetic In1−x
MnxSb solid solution and two types of magnetic cluster: ferromagnetic MnSb and ferrimagnetic Mn2Sb. XPS valence band and Mn 2p core level spectra have confirmed the presence of MnSb and Mn2Sb phases. TEM images show some manganese antimonide phase microinclusions with dimension between (30–40) nm.
New mechanism of solution of the k
B
T-problem in magnetobiology
Authors: Kanokov Zakirjon , Schmelzer Jürn , Nasirov Avazbek
Published: October 2009

The effects of ultralow-frequency or static magnetic and electric fields on biological processes is of huge interest for researchers due to the resonant change of the intensity of biochemical reactions, despite the energy in such fields being small in comparison with the characteristic energy k
B
T of the chemical reactions. In the present work, a simplified model to study the effects of weak static magnetic fields on fluctuations of the random ionic currents in blood is presented with a view to solving the k
B
T problem in magnetobiology. An analytic expression for the kinetic energy of the molecules dissolved in certain liquid media is obtained. The values of the magnetic field leading to resonant effects in capillaries are then estimated. The numerical estimates show that the resonant values of the energy of molecules in capillaries and the aorta are different. These estimates prove that under identical conditions, a molecule in the aorta gets 10−9 times less energy than the molecules in blood capillaries. Therefore, the capillaries are very sensitive to the resonant effect. As the magnetic field approaches the resonant value, the average energy of a molecule localized in a capillary is increased by several orders of magnitude as compared to its thermal energy. This amount of energy is sufficient to cause deterioration of certain chemical bonds.
Left ventricular myxoma: Confusing intracardiac mass in a patient with leukemia in remission
Authors: Tanindi Asli , Tacoy Gulten , Hizal Fatma , Turfan Murat , Ereren Emrah , Oktar Levent , Abaci Adnan
Published: October 2009

Cardiac myxomas are the most common primary benign tumors of the heart and appears particularly in the left atrium. Myxomas exhibit a wide spectrum of symptoms from asymptomatic to very serious according to the localisation of the tumours. Only 5% of these tumours occur in the right and left ventricles. We report an unusual case of a 21-year-old woman with a leukemia in remission, in whom routine transthorasic echocardiographic examination demonstrated an incidental left ventricular mass. The patient underwent successful resection of the left ventricular mass under cardiopulmonary bypass through the left atrial approach. Histopathologic examination was diagnostic for myxoma. In this case, the presentation of the mass was atypical for two reasons: the tumour was a cardiac myxoma in the left ventricular localisation and in a patient with leukemia in remission.
The effect of plant hormone indoleacetic acid (IAA) on hematological and biochemical parameters in mice
Authors: Morshed MH , Hossain M Shamm , Habib M Anwar , Ahmed MM Moinuddin , Ibrahim M , Ali M Umar , Islam M Azizul
Published: October 2009

The subacute toxicity of plant hormone indoleacetic acid (IAA) was studied on Swiss albino mice. The studies include the gross general observation such as changes in body weight, hematological profiles [total count of red blood cells (RBC) and white blood cells (WBC), differential count of WBC, platelet count, hemoglobin (Hb)%], biochemical parameters of blood [serum glutamate oxaloacetate transaminase (SGOT), serum glutamate pyruvate transaminase (SGPT), serum alkaline phospatase(SALP), creatinine] and histopathology of the liver, kidney, lung, spleen, heart and brain of both control and experimental day-1 for consecutive 14 days, showed no significant change of hematological and biochemical parameters. No abnormalities were also found in the histopathology of the liver, kidney, lung, spleen, heart and brain in the experimental group of animals following same dose when compared with control group. This preliminary toxicological study suggests that the plant hormone indoleacetic acid (IAA) may be used safely for agricultural purposes and as an external preservative DOI: 10.3329/bjpp.v22i1.3561 Bangladesh J Physiol Pharmacol 2006; 22(1/2) : 5-8
Validity of Self-Reported Weight and Height of Adolescents, Its Impact on Classification into BMI-Categories and the Association with Weighing Behaviour
Authors: De Vriendt Tineke , Huybrechts Inge , Ottevaere Charlene , Van Trimpont Inge , De Henauw Stefaan
Published: October 2009

This paper investigated the validity of self-reported height and weight of adolescents for the diagnosis of underweight, overweight and obesity and the influence of weighing behaviour on the accuracy. A total of 982 adolescents reported their height, weight, weighing behaviour and eating patterns in a questionnaire. Afterwards, their height and weight were measured and their Body Mass Index (BMI)-categories were determined using age- and gender-specific BMI cut-off points. Both girls and boys underreported their weight, whilst height was overestimated by girls and underestimated by boys. Cohen’s d indicated that these misreportings were in fact trivial. The prevalence of underweight was overestimated when using the self-reported BMI for classification, whilst the prevalence of overweight and obesity was underestimated. Gender and educational level influenced the accuracy of the adolescents’ self-reported BMI. Weighing behaviour only positively influenced the accuracy of the self-reported weight and not height or BMI. In summary, adolescents’ self-reported weight and height cannot replace measured values to determine their BMI-category, and thus the latter are highly recommended when investigating underweight, overweight and obesity in adolescents.