bluuebunny/crossref_metadata_2025 huggingface dataset:
Gaseous Nitrogen Losses from a Cambisol Cropped to Spring Wheat with Urea Sizes and Placement Depths
Authors: Khalil M. I. , Buegger F. , Schraml M. , Gutser R. , Richards K. G. , Schmidhalter U.
Published: June 2009

Globally identifying mitigation options for the emission of reactive N gases from agricultural soils is a research priority. We investigated the effect of urea size and placement depth on sources and emissions of N gases from a Cambisol cropped to spring wheat (Triticum aestivum L.). In Exp. 1, wheat received either prilled urea (PU) mixed within the soil, urea super granule (USG; diam. 10.1 mm) point‐placed at a soil‐depth of 7.5 cm, or no N fertilizer. In Exp. 2, wheat received either USG (diam. 10.2 mm) point‐placed at 2.5‐, 5.0‐, and 7.5‐cm soil depths, or no N fertilizer. In both experiments, maximum peaks for nitrous oxide (N2O) fluxes and nitrification were delayed by 2 to 3 wk in the USG compared with the PU treatment. The added 15N‐urea lost as 15N‐N2O over 116 d was only 0.01% for both PU and USG treatments in Exp. 1. This loss for USGs was higher in Exp. 2 (0.02–0.15%) measured over 70 d, mainly related to higher moisture‐induced denitrification. Temporal N2O fluxes were significantly related to changes in soil NO3−–N, water‐filled pore space and NH4+–N (R2 = 0.50, P < 0.05). However, the previous predictive model of Khalil et al. (2006) could best estimate its cumulative fluxes over time. The relative losses of ammonia (0.07–1.17%) and nitrogen oxides (0.19–1.54%) measured in Exp. 2 over 43 d decreased with increasing depths of USG placement. The USG point‐placed at the 5.0‐ and 7.5‐cm depths decreased the pooled gaseous N losses by 35 and 77%, respectively, over the shallower placement. The 15N results imply that soil N could be the major source of N2O emissions (79–97%). Field studies are suggested to validate our findings that the deeper placement of USG can decrease N emissions under arable cropping.
Mechanical Reinforcement of Soil by Willow Roots: Impacts of Root Properties and Root Failure Mechanism
Authors: Mickovski Slobodan B. , Hallett Paul D. , Bransby M. Fraser , Davies Michael C. R. , Sonnenberg Rene , Bengough A. Glyn
Published: June 2009

Plant roots have considerable impact on the mechanical stability of soil, but to date the underlying mechanisms have been poorly quantified. In this study, controlled laboratory studies of soil reinforced with willow trees (Salix viminalis cv Tora) found a strong correlation between the cross‐sectional area of soil covered by roots and shear reinforcement. We separated broken versus pulled‐out roots and measured individual root diameters crossing the shear‐plane. The shear strength of planted specimens compared with non‐planted specimens increased eight‐fold at 0.10‐m shear depth, more than four‐fold at 0.25‐m depth, and more than doubled at 0.40‐m depth. These data were used to evaluate several models of root‐reinforcement. Models based on catastrophic and simultaneous failure of all roots overpredicted reinforcement by 33% on average. Better agreement between experimental and model results was found for a stress‐based fiber‐bundle‐model, in which roots break progressively from weakest to strongest, with the load shared on the remaining roots at each step. Roots have a great capacity to reinforce soils, with existing models providing reasonable predictions of increased shear strength. However, deterministic understanding and modeling of the processes involved needs to consider root failure mechanisms. In particular, the role of root stiffness and root–soil adhesion is not considered in existing models of soil reinforcement by plant roots.
Distribution and Speciation of Nutrient Elements around Micropores
Authors: Jassogne Laurence , Hettiarachchi Ganga , Chittleborough David , McNeill Ann
Published: June 2009

In Australia a class of soils known as duplex soils covers approximately 20% of the continent. Their defining characteristic is a sharp texture contrast between the A (or E) and B horizon. The upper B horizon at the point of contact with the E horizon is often highly sodic and of such a high strength that root growth and proliferation, water conductivity, aeration, water storage, and water uptake are restricted. Roots growing in these soils rely on channels created by previous roots or cracks arising from shrink–swell forces associated with seasonal wetting and drying. Although the characteristics of rhizospheres compared with the soil matrix are well documented there is a paucity of knowledge about how long these changes persist after roots decay. This knowledge is fundamental to our understanding of root growth in duplex soils in which plants rely on pore networks formed by previous plants to proliferate in the subsoil. In this study we investigated the heterogeneous chemistry of micropores in situ using synchrotron‐based μ‐x‐ray fluorescence spectroscopy (XRF), μ‐x‐ray absorption near edge structure spectroscopy (XANES), and extended μ‐x‐ray absorption fine structure spectroscopy (EXAFS). The distribution maps of Ca, Mn, Fe, Cu, and Zn at micrometer resolution were collected using μ‐XRF. Subsequently, specific locations with higher concentrations (hot spots) of Mn, Fe, Cu, or Zn were selected and XANES and EXAFS spectra were collected to study the speciation of these elements around the micropore compared with the soil matrix. The μ‐XRF maps showed that Mn was depleted around one of the micropores studied but accumulated around another micropore. Copper and Zn accumulated around the micropores, whereas Ca was predominantly inside micropores. There was no difference between matrix and micropore surface with respect to the distribution of Fe. Around micropores Mn was present in reduced form (Mn II) and Fe was in its oxidized form (Fe III). Manganese and Cu were present in the form of phosphates, Fe as Fe oxides, and Zn as Zn phosphates and adsorbed Zn.
Quantifying the Aspect Effect: An Application of Solar Radiation Modeling for Soil Survey
Authors: Beaudette D. E. , O'Geen A. T.
Published: June 2009

Aspect angle is commonly used by soil scientists and ecologists as a qualitative proxy for landscape‐scale variation in microclimate and microclimate‐induced phenomena. This property of the landscape is simple to measure in the field and has a direct interpretation. Aspect angle is not easily integrated into more quantitative, physically based measures of landscape‐scale phenomena, however, because (i) solar geometry, not aspect angle, drives near‐surface processes, and (ii) there are numerical difficulties associated with periodic variables. We used the European Solar Radiation Atlas solar radiation model to generate an annual radiation load surface for subsequent modeling of microclimate‐coupled near‐surface processes at Pinnacles National Monument in California. Estimated annual solar radiation load values coupled with a local geologic map were used as predictor variables in a logistic regression model constructed to predict the spatial distribution of upland Mollisols. A total of 185 field observations were used to build the model, which had an 83 percent correctly classified (PCC) rate and a receiver operating characteristic (ROC) area of 0.78 to 0.96. A 50‐fold cross‐validation (repeated refitting of the model with a subset of observations) procedure indicated a mean classification error rate of 22%. Solar radiation modeling offers an exciting new approach for linking geographic information system and field observation in regions where microclimate‐coupled soil‐forming factors dominate pedogenesis. In addition, the quantification of a previously qualitatively described phenomena (the aspect effect) leads to a continuous description of soil taxonomic features at a much finer scale than is currently possible in soil survey.
Performance of a New Capacitance Soil Moisture Probe in a Sandy Soil
Authors: Parsons Lawrence R. , Bandaranayake Wije M.
Published: June 2009

Rapid population growth and increasing urban demand reduce the availability of water for agriculture in Florida. The water‐holding capacity of sandy soils in the Central Florida Ridge area is very poor (<0.10 m3 m−3). Improved soil water monitoring probes can help growers manage irrigation more efficiently and conserve water. This study evaluated a new soil water probe (ECH2O EC‐5 sensor, Decagon Devices, Pullman, WA) in terms of probe‐to‐probe signal variability, response to fertilizer‐induced salinity, and changes in soil temperature, soil volume sampled, sensitivity to pockets of air or dry soil, and performance in the field. Results were compared with an earlier version of a Decagon probe, the EC‐20. Results indicated that the new probe has several advantages. The EC‐5 was not sensitive to salinity or temperature fluctuations. Probe output change was almost zero when the salinity of the soil was increased by adding fertilizer to a soluble solids concentration of 14 g kg−1 When temperature was changed gradually from 3 to ∼38°C, probe output increased by only about 1%. Soil volume sampled by the probe was about 15 cm3 The change in probe response was negligible when soil cores up to 0.95 cm in diameter near the probe surface were removed. Probes responded well to changes in soil water content in the field. The EC‐5 probe output increased noticeably when bulk density was increased from 1.1 to 1.6 Mg m−3 Probe‐to‐probe output signal and response to bulk density variations can affect the estimation of field water content unless necessary correction factors are utilized. These probes can be useful for monitoring soil water movement, estimating soil water content, and scheduling irrigation.
Regional Study of No‐Till Impacts on Near‐Surface Aggregate Properties that Influence Soil Erodibility
Authors: Blanco-Canqui Humberto , Mikha M. M. , Benjamin J. G. , Stone L. R. , Schlegel A. J. , Lyon D. J. , Vigil M. F. , Stahlman P. W.
Published: June 2009

The extent to which tillage systems modify the near‐surface soil aggregate properties affecting soil's susceptibility to erosion by water and wind is not well understood. We hypothesized that an increase in soil organic carbon (SOC) content with conservation tillage systems, particularly no‐till (NT), may improve near‐surface soil aggregate properties that influence soil erodibility. This regional study assessed changes in aggregate resistance to raindrops, dry aggregate wettability, and dry aggregate stability as well as their relationships with changes in SOC content. Four long‐term (>19 yr) tillage systems including moldboard plow (MP), conventional till (CT), reduced till (RT), and NT were chosen across the central Great Plains at Hays and Tribune, KS, Akron, CO, and Sidney, NE. The kinetic energy (KE) of raindrops required to disintegrate 4.75‐ to 8‐mm aggregates from NT soils equilibrated at −0.03 and −155 MPa matric potential was between two and seven times greater than that required for MP and CT soils in the 0‐ to 2‐cm depth in all soils. At the same depth, the water drop penetration time (WDPT) in aggregates from NT soils was four times greater at Akron and Hays and seven times greater at Sidney and Tribune compared with that in plowed soils. Aggregates from NT soils were more stable under rain and less wettable than those from plowed soils particularly in the surface 0 to 5 cm, but RT had lesser beneficial effects than NT management. The SOC content increased with NT over MP and CT and explained 35% of the variability across soils in aggregate wettability and 28% of the variability in resistance to raindrops in the 0‐ to 2‐cm depth. Aggregate wettability explained 47% of the variability across soils in KE of raindrops required for the disintegration of aggregates. No‐till management did not affect dry aggregate‐size distribution and stability except at Akron where mean weight diameter (MWD) in RT and NT was 50% lower than in MP management in the 0‐ to 2‐cm depth. Aggregates in MP and CT soils were either stronger or equally strong when dry but less stable when wet than in NT soils. Overall, NT farming enhanced near‐surface aggregate properties affecting erosion by water but had small or no effects on dry aggregate stability.
Advances in data-driven analyses and modelling using EPR-MOGA
Authors: Giustolisi O. , Savic D. A.
Published: June 2009

Evolutionary Polynomial Regression (EPR) is a recently developed hybrid regression method that combines the best features of conventional numerical regression techniques with the genetic programming/symbolic regression technique. The original version of EPR works with formulae based on true or pseudo-polynomial expressions using a single-objective genetic algorithm. Therefore, to obtain a set of formulae with a variable number of pseudo-polynomial coefficients, the sequential search is performed in the formulae space. This article presents an improved EPR strategy that uses a multi-objective genetic algorithm instead. We demonstrate that multi-objective approach is a more feasible instrument for data analysis and model selection. Moreover, we show that EPR can also allow for simple uncertainty analysis (since it returns polynomial structures that are linear with respect to the estimated coefficients). The methodology is tested and the results are reported in a case study relating groundwater level predictions to total monthly rainfall.
A new method for spatial and temporal analysis of risk in water resources management
Authors: Simonovic Slobodan P.
Published: June 2009

Uncertainty in water resources management is in part about variability and in part about ambiguity. Both are associated with lack of clarity because of the behavior of all system components, lack of data, lack of detail, lack of structure to consider the water resources management problems, working and framing assumptions being used to consider the problems, known and unknown sources of bias, and ignorance about how much effort it is worth expending to clarify the management situation. The two major sources of variability are temporal and spatial heterogeneity. Temporal variability occurs when values fluctuate with time. Other values which are affected by spatial variability are dependent upon location of an area. A major part of the water resources management risk confusion relates to an inadequate distinction between the objective risk (real, physical) and subjective (perceived) risk. Because of the confusion between the two concepts, many characteristics of subjective risk are believed to be valid also for objective risk. The main objective of this paper is to initiate a discussion of the possible methodology for the reliability analysis of water resources systems that will be capable of: (a) addressing water resources uncertainty caused by variability and ambiguity, (b) integrating objective and subjective risk and (c) assisting the water resources management based on better understanding of temporal and spatial variability of risk.
Cellular-automata-based ecological and ecohydraulics modelling
Authors: Chen Qiuwen , Ye Fei , Li Weifeng
Published: June 2009

Spatially lumped models may fail to take into account the effects of spatial heterogeneity and local interactions. These properties sometimes are crucial to the dynamics and evolutions of ecosystems. This paper started from the fundamental aspects of CA and focused on the development and application of the approach to ecological and ecohydraulics modelling. Application cases include modelling of prey–predator dynamics by stochastic CA and simulation of riparian vegetation successions in a regulated river by rule-based CA. The results indicated that spatially explicit paradigms such as cellular automata (CA) have a strong capability to bridge the local processes and global patterns.
Recent advances in data-driven modeling of remote sensing applications in hydrology
Authors: Evora Noël D. , Coulibaly Paulin
Published: June 2009

Artificial neural networks (ANNs) are very effective statistical models for (1) extracting significant features or characteristics from complex data structures and/or for (2) learning nonlinear relationships involved in any input–output mapping. Another interesting aspect of ANN modeling is the fact that overall performance of these models is not greatly hampered by the presence of error-corrupted values in some input nodes. ANNs have gained interest in remote sensing applications as valuable inverse models that can retrieve physical characteristics of interest, such as precipitation, from remote sensing measurements collected from radars or satellites. The spatial coverage and high resolution of remote sensing measurements relative to ground-based measurements can improve the hydrological modeling of the water cycle at both local and global scales. This review paper intends to present recent advances in artificial neural network modeling of remote sensing applications in hydrology. This paper focuses on precipitation and snow water equivalent (SWE) retrievals from remote sensing data.
Introducing knowledge into learning based on genetic programming
Authors: Babovic Vladan
Published: June 2009

This work examines various methods for creating empirical equations on the basis of data while taking advantage of knowledge about the problem domain. It is demonstrated that the use of high level concepts aid in evolving equations that are easier to interpret by domain specialists. The application of the approach to real-world problems reveals that the utilization of such concepts results in equations with performance equal or superior to that of human experts. Finally, it is argued that the algorithm is best used as a hypothesis generator assisting scientists in the discovery process.
Uncertainty and sensitivity analysis techniques for hydrologic modeling
Authors: Mishra Srikanta
Published: June 2009

Formal uncertainty and sensitivity analysis techniques enable hydrologic modelers to quantify the range of likely outcomes, likelihood of each outcome and an assessment of key contributors to output uncertainty. Such information is an improvement over standard deterministic point estimates for making engineering decisions under uncertainty. This paper provides an overview of various uncertainty analysis techniques that permit mapping model input uncertainty into uncertainty in model predictions. These include Monte Carlo simulation, first-order second-moment analysis, point estimate method, logic tree analysis and first-order reliability method. Also presented is an overview of sensitivity analysis techniques that permit identification of those parameters that control the uncertainty in model predictions. These include stepwise regression, mutual information (entropy) analysis and classification tree analysis. Two case studies are presented to demonstrate the practical applicability of these techniques. The paper also discusses a systematic framework for carrying out uncertainty and sensitivity analyses.
Performance of electron beam irradiation for treatment of groundwater contaminated with acetone
Authors: Yoon Y. J. , Jung Y. J. , Han B. S. , Kang J. W.
Published: June 2009

The purposes of this study were to evaluate the efficiency of acetone removal by electron beam irradiation in groundwater and the effect of various conditions. According to the results, the removal kinetics of acetone were pseudo first-order, and the removal efficiencies were expressed to the (%) removal and G-values. By adding sulfite, it was confirmed that acetone was mainly degraded by the reaction with the hydrated electrons. The presence of nitrate caused the removal of acetone to decrease. But there was no significant effect of alkalinity on the removal of acetone. The effect of the initial pH values (pH 5 to 9) on the acetone removal efficiency was negligible, but the pH value decreases due to the formation of acidic compounds after irradiation. Consequently, the radiation-induced removal reactions of acetone followed the pseudo-first-order kinetic model; in addition to the initial concentration of acetone, nitrate and the absorbed dose were important factors in removing acetone from an aqueous solution using electron beam irradiation. The effects of general pH and alkalinity on the degrading acetone were negligible.
Fabrication of zero valent iron (ZVI) nanotube film via potentiostatic anodization and electroreduction
Authors: Jang Jun-Won , Jun Jung-Eui , Park Jae-Woo
Published: June 2009

Zero valent iron has been successfully used for the degradation of a wide range of contaminants. However, this reaction of using ZVI particle produces a large quantity of iron sludge. To solve the problem, we report the synthesis of self-organized nanoporous zero valent iron film treated with anodization and electro-reduction of iron foil. The iron nanotubes were fabricated in 1 M Na2SO4 + 0.5 wt% NaF electrolyte by supplying constant electric currents of 50 mV/s, and holding the potential at 20, 40 and 60 V for 20 min. Nanoporous shape was produced by anodic oxidation of iron film. After anodizing process, electro-reduction of nanoporous iron film converted crystallization iron oxide to zero valent iron. Electro-reduction process was carried out by electro-reducing with powersupply to and holding the potential at 20 V for 20 min. The surface of iron nanotube film was examined by BET and the thickness of the oxidized films was evaluated by scanning electron microscope (SEM). The crystalline structures of the fabricated films were evaluated using X-ray diffraction (XRD).
Development of statistical linear regression model for metals from transportation land uses
Authors: Maniquiz Marla C. , Lee Soyoung , Lee Eunju , Kim Lee-Hyung
Published: June 2009

The transportation landuses possessing impervious surfaces such as highways, parking lots, roads, and bridges were recognized as the highly polluted non-point sources (NPSs) in the urban areas. Lots of pollutants from urban transportation are accumulating on the paved surfaces during dry periods and are washed-off during a storm. In Korea, the identification and monitoring of NPSs still represent a great challenge. Since 2004, the Ministry of Environment (MOE) has been engaged in several researches and monitoring to develop stormwater management policies and treatment systems for future implementation. The data over 131 storm events during May 2004 to September 2008 at eleven sites were analyzed to identify correlation relationships between particulates and metals, and to develop simple linear regression (SLR) model to estimate event mean concentration (EMC). Results indicate that there was no significant relationship between metals and TSS EMC. However, the SLR estimation models although not providing useful results are valuable indicators of high uncertainties that NPS pollution possess. Therefore, long term monitoring employing proper methods and precise statistical analysis of the data should be undertaken to eliminate these uncertainties.
Evaluation of effectiveness of chemical and physical sewage treatment technologies for removal of retinoic acid receptor agonistic activity detected in sewage effluent
Authors: Inoue D. , Matsui H. , Sei K. , Hu J. , Yang M. , Aragane J. , Hirotsuji J. , Ike M.
Published: June 2009

Retinoic acid receptor (RAR) is a nuclear receptor involved in vertebrate morphogenesis, growth, cellular differentiation, and tissue homeostasis. Excess expression of the retinoid signaling can cause various developmental toxicities in animals and humans. We previously found that influents from sewage treatment plants (STPs) in Japan had a RAR agonistic activity and the activity cannot be removed completely by conventional biological treatments. In this study, we assessed the performance of chemical and physical sewage treatment technologies—ozonation, ultraviolet treatment, chlorination, coagulation using polyaluminium chloride (PAC) and ferric sulfate, and filtration with ultrafiltration (UF), nanofiltration (NF), and reverse osmosis (RO) membranes—in removal of RAR agonistic activity of STP effluent. All water treatment experiments were conducted in laboratory-scale reactors. The RAR agonistic activity of samples was measured using a yeast two-hybrid assay. Results showed that the effectiveness of tested technologies on the removal of RAR agonistic activity can be ranked as RO or NF > chlorination > ozonation > MF > UV > coagulation with ferric sulfate>>coagulation with PAC. Furthermore, the effectiveness of chlorination might rank lower because excess reaction might bring a side effect by producing some RAR agonistic by-product(s).
Evaluation of reflection and refraction in simulations of ultraviolet disinfection using the discrete ordinates radiation model
Authors: Ho C. K.
Published: June 2009

Simulations of UV disinfection systems require accurate models of UV radiation within the reactor. Processes such as reflection and refraction at surfaces within the reactor can impact the intensity of the simulated radiation field, which in turn impacts the simulated dose and performance of the UV reactor. This paper describes a detailed discrete ordinates radiation model and comparisons to a test that recorded the UV radiation distribution around a low pressure UV lamp in a water-filled chamber with a UV transmittance of 88%. The effects of reflection and refraction at the quartz sleeve were investigated, along with the impact of wall reflection from the interior surfaces of the chamber. Results showed that the inclusion of wall reflection improved matches between predicted and measured values of incident radiation throughout the chamber. The difference between simulations with and without reflection ranged from several percent near the lamp to nearly 40% further away from the lamp. Neglecting reflection and refraction at the quartz sleeve increased the simulated radiation near the lamp and reduced the simulated radiation further away from the lamp. However, the distribution and trends in the simulated radiation field both with and without the effects of reflection and refraction at the quartz sleeve were consistent with the measured data distributions.
Acute toxicity and relationship between metabolites and ecotoxicity during the biodegradation process of non-ionic surfactants: fatty-alcohol ethoxylates, nonylphenol polyethoxylate and alkylpolyglucosides
Authors: Jurado E. , Fernández-Serrano M. , Núñez-Olea J. , Luzón G. , Lechuga M.
Published: June 2009

The toxicity values of fatty-alcohol ethoxylates, nonylphenol polyethoxylate, and alkylpolyglucosides have been determined by applying assays with luminescent bacteria. Also, the relation between metabolites and ecotoxicity during the biodegradation process has been determined. The biodegradation tests were carried out according to the OECD 301 E test for ready biodegradability. In these tests a solution of the surfactant, representing the sole carbon source for the microorganisms, was tested in a mineral medium, inoculated and incubated under aerobic conditions in the dark. The toxicity of surfactants is related to their molecular structure (Quantitative Structure Activity Relationships, QSAR). For the alkylpolyglucosides, toxicity expressed as EC50 is related with the critical micelle concentration (CMC), the hydrophilic-lipophilic balance (HLB) of the surfactant, and the hydrophobic alkyl chain (R). The results indicate that toxicity increased as the CMC decreased and as the hydrophobicity increased and R rose. For fatty-alcohol ethoxylates, parameters characteristic studied have been HLB, number of units of ethylene oxide and the alkyl chain length. Relationships found are in agreement with the fact that increasing the alkyl chain length leads to a lower EC50, whereas increasing ethoxylation leads to a lower toxicity. An analysis of the behaviour of the toxicity and HLB again indicates that the toxicity was greater for surfactants with a smaller HLB. The evolution of the toxicity was studied over the biodegradation process, expressed as a percentage of inhibition. For all the non-ionic surfactants assayed, except for the nonylphenol polyethoxylate, a major decline was found in toxicity during the first days of the biodegradation assay and at all the concentrations tested.
Water quality and occurrence of water-borne diseases in the Douala 4th District, Cameroon
Authors: Ako Andrew Ako , Nkeng George Elambo , Takem Gloria Eyong Eneke
Published: June 2009

The monthly occurrence and mean age distribution of water-borne diseases in the Douala 4th District, Cameroon (1995–2006) were studied and probable causes of diseases spread were established. Diseases of interest included gastroenteritis, amoebic dysentery, typhoid fever and cholera. Water-borne disease occurrence was observed to follow a seasonal pattern with peaks occurring between the months of January and May followed by drops between June and October and rose again from November. Children below 5 years were found to be more vulnerable to diarrhoea, gastroenteritis, amoebic dysentery while persons between 15–44 years were more vulnerable to typhoid and cholera. Physico-chemically, water samples had turbidities varying between 5.5–86 NTU, pH values between 4.2 and 7.1 and zero residual chlorine. Bacteriological analysis showed that the total coliform count was averagely 74/100 ml, the faecal colform count was 43/100 ml and the faecal streptococci count was 27/100 ml. Lack of access to potable water, absence of sanitation facilities and environmental factors could be advanced as the probable causes of water-borne disease spread.
Medium-term performance and maintenance of SUDS: a case-study of Hopwood Park Motorway Service Area, UK
Authors: Heal K. V. , Bray R. , Willingale S. A. J. , Briers M. , Napier F. , Jefferies C. , Fogg P.
Published: June 2009

One of the main barriers to implementing SUDS is concern about performance and maintenance costs since there are few well-documented case-studies. This paper summarizes studies conducted between 2000 and 2008 of the performance and maintenance of four SUDS management trains constructed in 1999 at the Hopwood Park Motorway Service Area, central England. Assessments were made of the wildlife value and sedimentation in the SUDS ponds, the hydraulic performance of the coach park management train, water quality in all management trains, and soil/sediment composition in the grass filter strip, interceptor and ponds. Maintenance procedures and costs were also reviewed. Results demonstrate the benefits of a management train approach over individual SUDS units for flow attenuation, water treatment, spillage containment and maintenance. Peak flows, pond sediment depth and contaminant concentrations in sediment and water decreased through the coach park management train. Of the 2007 annual landscape budget of £15,000 for the whole site, the maintenance costs for SUDS only accounted for £2,500 compared to £4,000 for conventional drainage structures. Furthermore, since sediment has been attenuated in the management trains, the cost of sediment removal after the recommended period of three years was only £554 and, if the design is not compromised, less frequent removal will be required in future.
Nitrogen removal performance of anaerobic ammonia oxidation co-culture immobilized in different gel carriers
Authors: Zhu Gang-Li , Hu Yong-You , Wang Qi-Rui
Published: June 2009

Four materials were prepared as carriers for immobilizing anaerobic ammonium-oxidizing sludge. Nitrogen removal performance by these immobilized gel bead groups was evaluated. The removal ratios of ammonium and nitrite by CMC anammox-immobilized beads were 100% and 95.3% in 48 hours, respectively. The removal efficiencies of ammonium and nitrite by SA, PVA-SA and PVA anammox-immobilized beads were lower than the CMC beads. Subsequently, the physical properties of the beads were studied. PVA-SA was found to be the best support material among the four by comparing the case of the immobilization procedure, nitrogen removal efficiencies, and the costs of materials. PVA-SA gel entrapment was optimized by an orthogonal experiment. The SEM micrographs displayed that the surface structure of PVA-SA immobilized beads is loose and finely porous, which facilitates diffusion of the nitrogen. The SEM micrographs also clearly showed that anammox bacteria existed in the gel beads. All results clearly demonstrate that immobilizing anammox sludge in gel carriers is feasible and exhibit good performance. This research provided a new route to maintain sufficient amount of anammox sludge in a practical anammox reactor.
Community-focused greywater management in two informal settlements in South Africa
Authors: Armitage N. P. , Winter K. , Spiegel A. , Kruger E.
Published: June 2009

South Africa is struggling to provide services to the millions of poor people migrating to the major centres and living in informal settlements (shanty towns). Whilst the local authorities are generally able to provide potable water from the municipal network to communal taps scattered around the settlements, there is usually inadequate provision of sanitation and little or no provision for the drainage of either stormwater or greywater. This paper describes an investigation into ways of engaging with community structures in the settlements with a view to encouraging “self-help” solutions to greywater management requiring minimal capital investment as an interim “crisis” solution until such time that local and national government is able to provide formal services to everyone. The work was carried out in three settlements encompassing a range of different conditions. Only two are described here. It has become clear that the management of greywater has a low priority amongst the residents of informal settlements. The lack of effective political structures and the breakdown in communication with Ward Councillors and local government officials have contributed to the lack of progress. As the project progressed it became evident that greywater cannot be considered separately from stormwater, sanitation and refuse removal.
Advanced nitrogen removal via nitrite from municipal wastewater in a pilot-plant sequencing batch reactor
Authors: Yang Q. , Liu X. H. , Peng Y. Z. , Wang S. Y. , Sun H. W. , Gu S. B.
Published: June 2009

To obtain economically sustainable wastewater treatment, advanced nitrogen removal from municipal wastewater and the feasibility of achieving and stabilizing short-cut nitrification and denitrification were investigated in a pilot-plant sequencing batch reactor (SBR) with a working volume of 54 m3. Advanced nitrogen removal, from summer to winter, with effluent TN lower than 3 mg/L and nitrogen removal efficiency above 98% was successfully achieved in pulsed-feed SBR. Through long-term application of process control in pulsed-feed SBR, nitrite accumulation reached above 95% at normal temperature of 25°C. Even in winter, at the lowest temperature of 13°C, nitrite was still the end production of nitrification and nitrite accumulation was higher than 90%. On the basis of achieving advanced nitrogen removal, short-cut nitrification and denitrification was also successfully achieved. Compare to the pulse-feed SBR with fixed time control, the dosage of carbon source and energy consumption in pulsed-feed SBR with process control were saved about 30% and 15% respectively. In pulsed-feed SBR with process control, nitrogen removal efficiency was greatly improved. Moreover, consumption of power and carbon source was further saved.
Stochastic long term modelling of a drainage system with estimation of return period uncertainty
Authors: Thorndahl S.
Published: June 2009

Long term prediction of maximum water levels and combined sewer overflow (CSO) in drainage systems are associated with large uncertainties. Especially on rainfall inputs, parameters, and assessment of return periods. This paper proposes a Monte Carlo based methodology for stochastic prediction of both maximum water levels as well as CSO volumes based on operations of the urban drainage model MOUSE in a single catchment case study. Results show quite a wide confidence interval of the model predictions especially on the large return periods. Traditionally, return periods of drainage system predictions are based on ranking, but this paper proposes a new methodology for the assessment of return periods. Based on statistics of characteristic rainfall parameters and correlation with drainage system predictions, it is possible to predict return periods more reliably, and with smaller confidence bands compared to the traditional methodology.
Upflow anaerobic clarification tank (UACT) to upgrade existing anaerobic effluents
Authors: Diamantis V. I. , Verstraete W. , Aivasidis A.
Published: June 2009

The Upflow Anaerobic Clarification Tank (UACT) is of interest as a post-treatment step for high-rate anaerobic wastewater treatment systems. The UACT contributes to extra capture of methane from the raw wastewater. It also significantly facilitates the reuse of the treated water. The efficiency of the UACT process is demonstrated in this study using laboratory-scale reactors. The water produced by the UACT had a low total COD, in most cases below 145 mg/L and a soluble COD below 60 mg/L at surface loading rates between 0.1–0.4 m3/(m2 h) and hydraulic retention times between 5–6 h. The sludge bed of the UACT was characterised by 6–10 times higher substrate affinity (for ethanol, acetate and propionate) compared to the parent UASB and similar specific activity. The results suggest that a UASB followed by the UACT can, upon subsequent application of a rapid filtration, qualify as a total COD removal, no longer necessitating aerobic treatment.
Pollutant removal from oily wastewater discharged from car washes through sedimentation–coagulation
Authors: Rubí H. , Fall C. , Ortega R. E.
Published: June 2009

Wastewater from car washes represents a potential problem for the sewer system due to its emulsified oils and suspended material. Treatment of wastewater discharged from four car washes was investigated by sedimentation and coagulation. The effect of the coagulants Servical P (aluminium hydroxychloride), Servican 50 (poly(diallyldimethylammonium chloride)), aluminium sulfate and ferric chloride was evaluated. The achieved removal using sedimentation was of 82%, 88% 73% and 51% for oils, total suspended solids, COD, and turbidity, respectively. In the treatment by coagulation we achieved average efficiencies nearly to 74% for COD removal, greater than 88% in the case of total suspended solids removal and 92% in the case of turbidity and except the performance of Servican 50 greater than 90% in oil removal. We concluded that the oil residual concentration and COD in the treated water allows pouring it in the sewer system complying with the limits of the Mexican rule NOM-002-ECOL-1996 and it is possible even its reuse, at least in the case of the chassis washing of cars.
Simulation on combined rapid gravity filtration and backwash models
Authors: Han S. J. , Fitzpatrick C. S. B. , Wetherill A.
Published: June 2009

Combined rapid gravity filtration and backwash models have been applied to simulate filtration and backwash cycles. The simulated results from the backwash model suggest that an optimum air flow rate exists to maximise particle removal efficiency in the backwash operation for a certain backwash system. The simulation of combined rapid gravity filtration and backwash models suggests that the filter shouldn't be completely cleaned up in the backwash and a certain amount of particles retained on filter grains after backwash can be beneficial for subsequent filtration runs. This is consistent with the experimental results in the literature.
Effect of key operating parameters on the non-catalytic wet oxidation of olive mill wastewaters
Authors: Chatzisymeon E. , Diamadopoulos E. , Mantzavinos D.
Published: June 2009

The non-catalytic wet air oxidation (WAO) of olive mill wastewaters was investigated. The effect of operating conditions, such as initial organic loading (1,000 and 4,500 mg/L COD), reaction temperature (140 and 180°C), treatment time (1 and 4 h), initial pH (4.8 and 7) and the use of 500 mg/L H2O2 as an additional oxidant, on treatment efficiency was assessed implementing a factorial experimental design. Of the five parameters tested, the first two had a considerable effect on COD removal, while treatment time was of no significance implying that all oxidation reactions occur during the first hour of treatment. Although the level of mineralization was generally moderate, this was accompanied by nearly complete total phenols and color removal. The analysis was repeated at more intense conditions, i.e. initial COD up to 8,000 mg/L and reaction temperature up to 200°C; at this level, none of the studied effects were important. However, at optimal experimental conditions (i.e. 180°C, 1 h treatment and initial COD of 8,100 mg/L) WAO yielded 34, 94 and 74% removal of COD, total phenols and color respectively. Moreover, ecotoxicity to V. fischeri was slightly reduced after 2 h of treatment at the above conditions.
Hydraulic performance of a mature wetland treating milkhouse wastewater and agricultural runoff
Authors: Speer S. , Champagne P. , Crolla A. , Kinsley C.
Published: June 2009

A tracer study is an efficient method of determining flow dynamics within a constructed wetland. In previous studies, a number of tracer studies have been carried out on various constructed wetlands covering a wide range of configurations. From these tracer studies it is evident that all constructed wetlands perform differently and generally with less efficiency than assumed by theoretical design computations. During the summer of 2004, a tracer study was performed on a constructed wetland located in Embrun, Ontario (Canada) treating milkhouse wastewater and agricultural runoff to determine its actual hydraulic performance. Sediment height and vegetation density profiles were also obtained and examined to explain the preferential flow pathways that were observed during the tracer analysis. It was determined that the constructed wetland had an effective treatment area representing 79% of the total area, and that the hydraulic efficiency of the system was 74%. Examination of the sediment height and vegetation density profiles resulted in no evidence of physical pathways that could be attributed to the establishment of preferential flow. The hydraulic efficiency was therefore attributed to the inflow and outflow layout of the constructed wetland cell, combined with wind induced mixing.
Development of a modern curriculum in software engineering at master level across countries
Authors: Bothe Klaus , Budimac Zoran , Cortazar Rebeca , Ivanovic Mirjana , Zedan Hussein
Published: June 2009

A strong need for new approaches and new curricula in different disciplines in European education area still exists. It is especially the case in the field of software engineering which has traditionally been underdeveloped in some areas. The curriculum presented in this paper is oriented towards undergraduate students of informatics and engineering. The proposed approach takes into account integration trends in European educational area and requirements of the labour market. The aim of this paper is to discuss the body of knowledge that should be provided by a modern curriculum in software engineering at a master level. Also the techniques used in development and implementation of such curriculum at different universities will be described. The presented ideas are based on the experience gained in the 3 year TEMPUS1 project 'Joint MSc Curriculum in Software Engineering', which established joint master studies in software engineering. Over a three-year interval, the project managed to define a new and joint curriculum, create teaching materials and deliver the curriculum in two institutions.
Influence of information and communication technologies on decentralization of organizational structure
Authors: Cudanov Mladen , Jasko Ondrej , Jevtic Milos
Published: June 2009

This paper presents research on influence of information and communication technologies on decentralization of organizational structure. An empirical research was conducted, in which decentralization was described by dominant management style was compared to the level of composite index of ICT adoption. Also, consulting experience in four major Serbian companies was used to further elaborate and explain the results in the context of modern literature and practice. Conclusions were that ICT adoption is more frequently expressed in decentralized companies, empirically described by dominant liberal style of management, although ICT adoption can also lead to centralization in some cases, depending on other factors in the organization.
Software process improvement in SMEs: A comparative view
Authors: Mishra Deepti , Mishra Alok
Published: June 2009

The majority of software development organizations all over the world are small and medium enterprises. These organizations have realized that it is crucial for their business to improve their processes and working methods but they are lacking the knowledge and resources to do it. Successful implementation of SPI methodologies in small and medium-sized software enterprises (SMEs) is generally not possible because such organizations are not capable of investing the cost of implementing these programs. Limited resources and strict deadlines to complete the projects make it further difficult to implement SPI programs which can also affect quality issues in software project. There are various SPI methodologies to address these issues which have been also deployed in these organizations. In this paper, recent and significant SPI methodologies (OWPL, ASPE-MSC, iFLAP, PRISMS, SPM, MESOPYME) for SMEs are compared and discussed. This will facilitate the maturity of software process improvement in SMEs, standardization and also contribute in the development of automation tools for SPIs in future.
Architectures of DICOM based PACS for JPEG2000 medical image streaming
Authors: Dinu Dragan , Ivetic Dragan
Published: June 2009

Delivering of medical image content to mobile/embedded devices with low storage and processing capabilities and low resolution displays is a challenging, but important task for achieving ubiquitous computing in modern hospital environments. The common approaches in industry and technical literature employ JPEG2000 compression and image streaming. Beside image compression, JPEG2000 facilitates image streaming. Different sized images are extracted from one codestream with minimal spatial distortion within decompressed image. We developed DICOM2000 syntax which enables JPEG2000 streaming over DICOM networks. DICOM2000 brings compression and streaming power of JPEG2000 to DICOM which is the standard for medical image interchange. It enables transmission of best quality medical images suited for client device processing and display capabilities. In this paper communication architectures of DICOM2000 based PACS are compared with the common architectures of DICOM based PACS. For the purpose of the paper, these communication architectures are categorized, named, and described. At the end, the advantages of the DICOM2000 based PACS over standard PACS are pointed up.