bluuebunny/crossref_metadata_2025_split huggingface dataset:
Simulation and optimization model for irrigation planning and management
Authors: Kuo Sheng‐Feng , Liu Chen‐Wuing 
Published: October 2003

AbstractA simulation and optimization model was developed and applied to an irrigated area in Delta, Utah to optimize the economic benefit, simulate the water demand, and search the related crop area percentages with specified water supply and planted area constraints. The user interface model begins with the weather generation submodel, which produces daily weather data, which is based on long‐term monthly average and standard deviation data from Delta, Utah. To simulate the daily crop water demand and relative crop yield for seven crops in two command areas, the information provided by this submodel was applied to the on‐farm irrigation scheduling submodel. Furthermore, to optimize the project benefit by searching for the best allocation of planted crop areas given the constraints of projected water supply, the results were employed in the genetic algorithm submodel. Optimal planning for the 394·6‐ha area of the Delta irrigation project is projected to produce the maximum economic benefit. That is, projected profit equals US$113 826 and projected water demand equals 3·03 × 106 m3. Also, area percentages of crops within UCA#2 command area are 70·1%, 19% and 10·9% for alfalfa, barley and corn, respectively, and within UCA#4 command area are 41·5%, 38·9%, 14·4% and 5·2% for alfalfa, barley, corn and wheat, respectively. As this model can plan irrigation application depths and allocate crop areas for optimal economic benefit, it can thus be applied to many irrigation projects. Copyright © 2003 John Wiley & Sons, Ltd.
Propagation of drought through groundwater—a new approach using linear reservoir theory
Authors: Peters E. , Torfs P. J. J. F. , van Lanen H. A. J. , Bier G. 
Published: October 2003

AbstractThe effect of drought on groundwater heads and discharge is often complex and poorly understood. Therefore the propagation of a drought from groundwater recharge to discharge and the influence of aquifer characteristics on the propagation was analysed by tracking a drought in recharge through a linear reservoir. The recharge was defined as a sinusoid function with a period of 1 year. The decrease in recharge owing to drought was simulated by multiplying the recharge during 1 year with a drought fraction between 0 and 1, which represents a decrease in the recharge of 100 to 0%, respectively. The droughts were identified using the threshold level approach, with a threshold that is constant in time. For this case analytical formulations were derived, which express the drought duration and deficit in the groundwater discharge in terms of the decrease in recharge, the reservoir coefficient that characterizes aquifer properties and the height of the threshold level. The results showed that the delay in the groundwater system caused a shift of the main part of the decrease in recharge from the high‐flow to the low‐flow period. This resulted in an increase in drought deficit for discharge compared with the drought deficit for recharge. Also the development of multiyear droughts caused an increase in drought deficit. The attenuation in the groundwater system caused a decrease in drought deficit. In most cases the net effect of these processes was an increase of drought deficit as a result of the propagation through groundwater. Only for small droughts the deficit decreased from recharge to discharge. The amount of increase or decrease depends on the reservoir coefficient and the severity of the drought. Under most conditions a maximum in the drought deficit occurred for a reservoir coefficient of around 200 days. Copyright © 2003 John Wiley & Sons, Ltd.
Soil moisture–temperature relationships: results from two field experiments
Authors: Lakshmi Venkat , Jackson Thomas J. , Zehrfuhs Diane 
Published: October 2003

AbstractThis paper analyses data from two field experiments in Chickasha, Oklahoma, and Tifton, Georgia, carried out in July 1999 and June 2000 respectively. The observations on soil moisture at two depths, viz. 0–2·5 and 0–5·0 cm, surface temperature, and temperatures at 1, 5 and 10 cm depths are analysed. The relationship between the soil moisture and the temperature variability in time is examined as a function of vegetation type and location. Results from these experiments show that, during drydown, surface temperature shows an increase that corresponds to a decrease in the soil moisture. Linear models for prediction of soil moisture (at both depths) using surface temperature observations are examined. Copyright © 2003 John Wiley & Sons, Ltd.
Application of generalized contaminant retardation factor to a multi‐phase system
Authors: Kim Song‐Bae , Kim Dong‐Ju 
Published: October 2003

AbstractIn this study, a generalized contaminant retardation factor applicable to a multiphase system where various types of colloids exist simultaneously with contaminants is derived and incorporated into an equilibrium model which is successfully applied to experimental data for which phenanthrene was used as hydrophobic organic contaminants and dissolved organic matter (DOM) or bacteria as mobile carriers. Based on the parameter values for the experimental data regarding the association of phenanthrene with solid matrix, DOM and various bacterial isolates, numerical experiments are performed to examine the transport behaviour of hydrophobic organic contaminants in various types of the multiphase system. Numerical experiments demonstrate that the extent of contaminant transport enhancement depends on the adsorption affinity of the colloid, its concentration and its mobility, and that the importance of a third phase to contaminant transport needs to be evaluated carefully with respect to the relevance of experimental conditions applied to realistic environmental conditions. Copyright © 2003 John Wiley & Sons, Ltd.
Application of a neural network model in establishing a stage–discharge relationship for a tidal river
Authors: Supharatid Seree 
Published: October 2003

AbstractThis paper presents the applicability of neural network (NN) modelling for forecasting and filtering problems. The multilayer feedforward (MLFF) network was first constructed to forecast the tidal‐level variations at the mouth of the River Chao Phraya in Thailand. Unlike the well‐known conventional harmonic analysis, the NN model uses a set of previous data for learning and then forecasting directly the time‐series of tidal levels. It was found that lead time of 1 to 24 hourly tidal levels can be predicted successfully using only a short‐time hourly learning data. The MLFF network was further used to establish a stage–discharge relationship for the tidal river. The results show a considerably better performance of the NN model over the conventional models. In addition, the stage–discharge relationship obtained by the NN model can indicate reasonably well the important behaviour of the tidal influences. Copyright © 2003 John Wiley & Sons, Ltd.
Hillslope‐swamp interactions and flow pathways in a hypermaritime rainforest, British Columbia
Authors: Fitzgerald D. F. , Price J. S. , Gibson J. J. 
Published: October 2003

AbstractThe process of water delivery to a headwater stream in a hypermaritime rainforest was examined using a variety of physical techniques and tracing with dissolved organic carbon (DOC) and the stable isotopes of water. Headwater swamps, often the major discharge zones for water draining off steep forest slopes, strongly affect the physical and chemical character of streamflow in the region. The headwater swamp selected for detailed investigation was sustained by relatively constant groundwater input from the steep colluvial slopes that maintained the water table above the ground surface. During significant storm events the water table rose quickly and the swamp expanded to engulf marginal pools that developed rapidly on the adjacent ground surfaces. The corresponding release of surface water directly to the stream typically comprised up to 95% of total stream discharge. The proportion of groundwater seepage to the stream by matrix flow (<1%) and via macropore‐fed springs (up to 73%) increased during the recession period, but could not be sustained over the longer term. In more protracted drying periods, deep groundwater contributions to the stream were routed first to the headwater swamp.Dissolved organic carbon (DOC) in the stream, measured daily or more frequently during storm events, was found to be directly proportional to discharge, owing to the domination of DOC‐rich headwater‐swamp water sources. Although δ18O and δ2H composition of rainwater, groundwater and stream flow were found to be similar, deuterium excess (d  δ2H − 8δ18O) of water components was often found to be distinct, and suggested short water residence times of roughly 12 days for one event. Overall, observations of a typical headwater swamp reveal that the groundwater regime is dominated by rapid infiltration and short, emergent flow paths. With a relatively short turnover time, potential disturbances to the system by harvesting of upslope areas can be expected to occur rapidly. Forest managers can mitigate some of the harmful effects of logging operations by respecting the integrity of headwater wetland systems. The nature and magnitude of such perturbations will require further study. Copyright © 2003 John Wiley & Sons, Ltd.
Water–air temperature relationships in a Devon river system and the role of flow
Authors: Webb B. W. , Clack P. D. , Walling D. E. 
Published: October 2003

AbstractThe nature of the water–air temperature relationship, and its moderation by discharge, were investigated for catchments ranging in size from 2·1 to 601 km2 in the Exe basin, Devon, UK and for data relating to hourly, daily and weekly time bases. The sensitivity and explanatory power of simple water–air temperature regression models based on hourly data were improved by incorporation of a lag, which increased with catchment size, although relationships became more sensitive and less scattered as the time base of data increased from hourly to weekly mean values. Significant departures from linearity in water–air temperature relationships were evident for hourly, but not for daily mean or weekly mean, data. A clear tendency for relationships between water and air temperatures to be stronger and more sensitive for flows below median levels was apparent, and multiple regression analysis also revealed water temperature to be inversely related to discharge for all catchments and time‐scales. However, discharge had a greater impact in accounting for water temperature variation at shorter time‐scales and in larger catchments. Copyright © 2003 John Wiley & Sons, Ltd.
Suspended sediment yield and metal contamination in a river catchment affected by El Niño events and gold mining activities: the Puyango river basin, southern Ecuador
Authors: Tarras‐Wahlberg N. H. , Lane S. N. 
Published: October 2003

AbstractThe suspended sediment yield and the transfer of polluted sediment are investigated for the Puyango river basin in southern Ecuador. This river system receives metal (Cd, Cu, Hg, Pb and Zn) and cyanide pollution generated by mining, and is associated with large‐scale hydrological variability, which is partly governed by El Niño events. Field sampling and statistical modelling methods are used to quantify the amount of mine tailings that is discharged into the basin. Annual suspended sediment yields are estimated using a novel combination of the suspended sediment rating method and Monte Carlo simulations, which allow for propagation of the uncertainties of the calculations that lead to final load estimates. Geochemical analysis of suspended and river bed sediment is used to assess the dispersion and long‐term fate of contaminated sediment within the river catchment. Knowledge of the inter‐ and intra‐annual variation in suspended sediment yield is shown to be crucial for judging the importance of mining discharges, and the extent to which the resultant pollution is diluted by river flows. In wet years, polluted sediments represent only a very small proportion of the yield estimates, but in dry years the proportion can be significant. Evidence shows that metal contaminated sediments are stored in the Puyango river bed during low flows. Large flood events flush this sediment periodically, both on an annual cycle associated with the rainy season, and also related to El Niño events. Therefore, environmental impacts of mining‐related discharges are more likely to be severe during dry years compared with wet years, and in the dry season rather than the wet season. The hydrological consequences of El Niño events are shown to depend upon the extent to which these events penetrate inland. It is, thus, shown that the general conclusion that El Niño events can significantly affect suspended sediment yields needs evaluation with respect to the particular way in which those events affect a given catchment. Copyright © 2003 John Wiley & Sons, Ltd.
Contribution of membrane‐associated prostaglandin E2 synthase to bone resorption
Authors: Saegusa Masatomo , Murakami Makoto , Nakatani Yoshihito , Yamakawa Kiyofumi , Katagiri Mika , Matsuda Koichi , Nakamura Kozo , Kudo Ichiro , Kawaguchi Hiroshi 
Published: October 2003

AbstractThis study initially confirmed that, among prostaglandins (PGs) produced in bone, only PGE2 has the potency to stimulate osteoclastogenesis and bone resorption in the mouse coculture system of osteoblasts and bone marrow cells. For the PGE2 biosynthesis two isoforms of the terminal and specific enzymes, membrane‐associated PGE2 synthase (mPGES) and cytosolic PGES (cPGES) have recently been identified. In cultured mouse primary osteoblasts, both mPGES and cyclooxygenase‐2 were induced by the bone resorptive cytokines interleukin‐1, tumor necrosis factor‐α, and fibroblast growth factor‐2. Induction of mPGES was also seen in the mouse long bone and bone marrow in vivo by intraperitoneal injection of lipopolysaccharide. In contrast, cPGES was expressed constitutively both in vitro and in vivo without being affected by these stimuli. An antisense oligonucleotide blocking mPGES expression inhibited not only PGE2 production, but also osteoclastogenesis and bone resorption stimulated by the cytokines, which was reversed by addition of exogenous PGE2. We therefore conclude that mPGES, which is induced by and mediates the effects of bone resorptive stimuli, may make a target molecule for the treatment of bone resorptive disorders. J. Cell. Physiol. 197: 348–356, 2003© 2003 Wiley‐Liss, Inc.
Water treatment using sequenced ozonation and SBR biofilm reactors
Authors: Carini D , Dunn IJ , Morbidelli M 
Published: October 2003

AbstractThe degradation of 3‐methylpyridine (3MEP), a model heterocyclic industrial molecule, was performed in a sequential batch ozonation–biofilm process. Four process steps (bubble‐column ozonation, heterotrophic biofilm degradation, biofilm nitrification, and biofilm denitrification) were combined in different sequences. Three packed‐bed biofilm reactors were started up so as to have separate, specific activities (heterotrophic, nitrification and denitrification). Batch experiments with acetate, ammonia, and nitrate proved that all reactors displayed degradation activity for all substances. Different batch sequences of these reactors were tested with the products of batch ozonation of 3MEP as the first step. The best results were obtained using a two‐step process, in which the ozonation was followed by a single fluidized‐bed, heterotrophic biofilm reactor. The high C/N ratio of 3MEP and the appreciable non‐specific activity of this reactor made it possible to achieve all the biodegradation in the one reactor. Establishing the optimal batch ozonation time (80 min) was determined by an ozone electrode and by stopping the process when the dissolved ozone concentration rose above an initial low level. The identifiable products of 3MEP ozonation were nitrate, acetate, formate, pyruvate, oxalate and ammonium. A C‐balance, compared with TOC measurement, indicated that about 50% of the carbon was in unidentified, but biogradable, ozonation products. Copyright © 2003 Society of Chemical Industry
Combination of biological and chemical processes for the treatment of textile wastewater containing reactive dyes
Authors: Libra Judy A , Sosath Frank 
Published: October 2003

AbstractThe treatment of a segregated textile wastewater containing reactive dyes was investigated in two continuous‐flow process trains using ozonation and biological processes. The degree of decolorization and dissolved organic carbon (DOC) removal achieved by ozonation followed by aerobic treatment (two‐stage) was compared with that found when an anaerobic and aerobic pretreatment was added (four‐stage). Although the biological pretreatment reduced color by ∼70%, similar amounts of ozone were required in both trains to achieve high degrees of overall removal of color and DOC. In both trains, ozonation increased biodegradability in the following aerobic reactor, however, in order to reach ∼80% overall DOC removal, a specific ozone absorption (A*) of ∼6 gO3 gDOCo−1 was required and >50% of the DOC was mineralized in the ozone reactor. A comparison of cost estimates based on investment and operating costs for the process alternatives showed that a four‐stage train would reduce costs only if it enabled a decrease in A* to less than 2 gO3 gDOCo−1. Difficulties in comparing treatment processes for segregated vs full‐stream wastewaters are discussed. Copyright © 2003 Society of Chemical Industry
Fabrication by three‐phase emulsification of pellicular adsorbents customised for liquid fluidised bed adsorption of bioproducts
Authors: Jahanshahi Mohsen , Pacek Andrzej W , Nienow Alvin W , Lyddiatt Andrew 
Published: October 2003

AbstractA novel dense pellicular adsorbent, custom‐designed for liquid fluidised bed adsorption of protein bioproducts, has been fabricated by coating zirconia–silica particles with agarose gel in a three‐phase emulsification process. A slurry feedstock comprising solid zirconia–silica particles (120 µm average diameter) suspended in an aqueous solution of agarose was emulsified in an oil–surfactant mixture in a stirred vessel to yield composite droplets. These were subsequently stabilised by cooling to form spherical pellicular particles characterised by a porous, pellicular coat cast upon a solid core. The impact of agitation speed, surfactant concentration, oil viscosity and slurry composition upon the pellicle depth and overall particle diameter was investigated. Pellicle depth decreased with increasing impeller speed and decreased oil viscosity, whilst increased slurry viscosity enhanced that parameter. Initial increases from low concentrations of Span 80 surfactant (0.1% w/v oil) reduced the depth of the agarose pellicle, but the highest values investigated (1.5% w/v oil) promoted particle aggregation. The fluidisation behaviour of particles fabricated under various conditions was characterised by the measurement of expansion coefficients and axial dispersion coefficients for the liquid phase when operated in a standard fluidised bed contactor. Both parameters were found to be comparable or superior to those reported for conventional, composite fluidised bed adsorbents. The controlled coating of porous agarose upon a solid core to yield specific pellicular geometries is discussed in the context of the fabrication of adsorbents customised for the recovery of a variety of bioproducts (macromolecules, nanoparticulates) from complex particulate feedstocks (whole broths, cell disruptates and unclarified bio‐extracts). Given the agreement between the size of the pellicular particles and the trends expected from theory, the large‐scale manufacture of such particles for customised industrial use is recommended. Copyright © 2003 Society of Chemical Industry
Ozonation of vinasse in acid and alkaline media
Authors: Martín Santos MA , Fernández Bocanegra JL , Martín Martín A , García García I 
Published: October 2003

AbstractThe production of ethanol by fermentation and subsequent distillation generates wastewater known as ‘vinasse’. This waste is highly polluting on account of its high organic load and antibacterial activity—which arises from the presence of phenolic compounds that reduce the efficiency of the detoxification treatments best suited to this type of waste (eg anaerobic digestion). This can be avoided by using a pre‐treatment based on a chemical oxidant (ozone) at an acid or alkaline pH. Ozonation in acid media provides more selective elimination of phenolic compounds and a more readily biodegradable waste (ie an increased BOD5/COD ratio). Copyright © 2003 Society of Chemical Industry
High‐level production of recombinant His‐tagged rhamnulose 1‐phosphate aldolase in Escherichia coli
Authors: Vidal L , Durany O , Suau T , Ferrer P , Benaiges MD , Caminal G 
Published: October 2003

AbstractAn expression system based on Escherichia coli and the T5 promoter allowed the overproduction of a his‐tagged rhamnulose‐1‐phosphate aldolase (RhuA; EC 4.1.2.19), an enzyme with applications in the production of deoxyazasugars and deoxysugars compounds. Shake flask and bioreactor cultivation with E coli M15 (pQErham) were performed under different media and inducing conditions for RhuA expression. A Defined Medium (DM) with glucose as carbon source gave a high volumetric and enzyme productivity (3460 AU dm−3 and 288 AU dm−3 h−1 respectively) compared with Luria–Bertoni (LB) medium (2292 AU dm− 3 and 255 AU dm−3 h−1). The minimum quantity of (isopropyl‐β‐D‐thiogalactoside) IPTG for optimal induction was estimated in 18–20 µmol IPTG gDCW−1. The highest volumetric production of RhuA (8333 AU dm−3) was obtained when IPTG was added in the late log‐phase. No significant differences were found in specific RhuA activity for induction temperatures of 30 and 37 °C. An effective two‐step purification process comprising affinity chromatography and gel permeation has been developed (overall recovery 66.5%). These studies provide the basis for the further development of an integrated process for recombinant RhuA production suitable for biotransformation applications. Copyright © 2003 Society of Chemical Industry
Simulation of continuous stirred ultrafiltration process: an approach based on analytical solution coupled with turbulent back transport
Authors: Bhattacharjee Chiranjib , Datta Siddhartha 
Published: October 2003

AbstractA mass transfer model based on unsteady state mass balance over the concentration boundary layer, coupled with back transport resulting from the stirring action, opposing ultrafiltrate flux, has been developed in the present study. This model uses semi‐infinite consideration to solve the governing partial differential equation by the Laplace transformation method, which gives the analytical solution of the concentration profile. During the solution procedure, pseudo‐steady state assumption has been used, as a consequence of which volumetric flux and turbulent back transport flux have been taken as constants. Once the analytical expression for the concentration profile has been found, an iterative technique has been developed for simulating flux and rejection under any specified operating condition. The prediction from this model is found to be in good agreement with experimental results obtained during continuous stirred ultrafiltration of PEG‐6000 solution using a cellulose acetate membrane of 5000 Da molecular weight cut‐off. The average absolute deviation in the prediction of permeate flux has been found to be 5.6% and that for the prediction of rejection was 6.4%. Copyright © 2003 Society of Chemical Industry