bluuebunny/crossref_metadata_2025 huggingface dataset:
Treatment of Wastewater Phosphate by Reductive Dissolution of Iron
Authors: Robertson W. D.
Published: July 2010

A new method for the treatment of wastewater phosphate is presented that relies on reductive iron dissolution (RID process). It is analogous to existing treatment methods that use iron salts (e.g., FeCl2) to precipitate P from wastewater, except that in this case ferrous iron is made available by the reductive dissolution of ferric iron solids that are contained in a reactive porous media. The ferric solids are minerals such as amorphous Fe(OH)3 that occur naturally in soils and sediments. A laboratory column study and a pilot scale field trial demonstrated that these solids are susceptible to reductive dissolution when mixed with sewage effluent, resulting in increased Fe(II) in solution. This promotes the precipitation of Fe(II)‐P solids and then Fe(III)‐P solids when the effluent is subsequently oxidized. Both experiments demonstrated the ability of the RID media to passively solubilize consistent, moderate concentrations of Fe (1–9 mg L−1) over extended periods (2–3 yr). In the column test, influent PO4 of 9.0 ± −3.7 mg P L−1 was lowered to 2.1 ± 1.1 mg P L−1. In the field trial, influent PO4 of 10.2 ± 6.0 mg P L−1 was lowered to <0.05 mg P L−1. This technique may be attractive for use with smaller wastewater treatment systems such as septic systems, because it can be maintenance‐free for long periods and it avoids excess sludge accumulation.
Denitrification in South Carolina (USA) Coastal Plain Aquatic Sediments
Authors: Aelion C. Marjorie , Shaw J. Nikki
Published: July 2010

Denitrification rates in aquatic sediments from three sites upland of high salinity estuaries were measured to compare nitrate (NO−3) removal by sediment bacteria. The study sites included two blackwater creeks that drain to coastal inlets (one in an undeveloped coastal forest and the second in a suburban residential development) and drainage pond on a golf course. Two to 20 mmol NO−3 kg−1 soil was added to microcosms and the acetylene block technique was used to estimate denitrification. Nitrate, nitrous oxide (N2O) and ammonium (NH+4) concentrations were monitored over time. The rate and efficiency of denitrification was low at the 2 mmol NO−3 kg−1 addition and increased proportionally with NO−3 added. Across all treatments, the golf course sediment that received consistent N inputs in situ had the most rapid and greatest N2O production, while the salt marsh in the undeveloped area had the least. The NH+4 concentrations remained constant and low (2 mmol N kg−1) except at the undeveloped, forested Oyster Creek (8 mmol NH+4‐N kg−1). In most cases, the majority of NO−3 removal did not occur until 24 to 48 h of incubation, regardless of N2O production. During typical low‐ and no‐flow periods, this time frame may be adequate for slow diffusion of nutrients and removal of NO−3 prior to transport to coastal estuaries or ground water, particularly at the golf course site. However, this time frame may not be adequate during rapid water and nutrient transport due to severe storm events typical of this region.
Toward Site‐Specific Design Standards for Animal‐Waste Lagoons: Protecting Ground Water Quality
Authors: Ham J. M. , DeSutter T. M.
Published: July 2010

abstract

Seepage losses from animal‐waste lagoons can affect ground water quality, if facilities are not properly sited, designed, and constructed. Most states in the Great Plains stipulate that earthen lagoons cannot seep more than some specified rate (mm d−1). These criteria often apply to the entire state and all livestock species, although ground water vulnerability and waste characteristics are highly variable from site to site. Because of this variability, statewide “blanket” regulations may overregulate some producers and underregulate others. Furthermore, wide disparity exists in seepage allowances among neighboring states, and regulations often are influenced by public opinion rather than scientific findings. This paper argues that lagoon design should be site specific and presents a logical framework to determine the maximum allowable seepage rate for a given location and type of operation (e.g., dairy, swine, cattle feedlot). Site‐specific factors, such as soil properties, depth to water table, and chemistry of the waste, are used to arrive at lagoon performance standards that minimize long‐term risk. The decision process within the framework is presented as a conceptual model for lagoon permitting and may need to be customized to meet the requirements of each state. Nevertheless, use of site‐specific design criteria will ensure that manure storages are adequate (e.g., plastic‐lined lagoons) in regions with vulnerable ground water, while providing reduced lagoon construction costs (lower cost of soil‐lined lagoons) for producers who site their operations in areas of low risk. To complement the site‐specific approach, the whole‐lagoon seepage rate should be measured after construction to verify that the prescribed performance criteria have been met.
Water Quality Changes from Riparian Buffer Restoration in Connecticut
Authors: Clausen J. C. , Guillard K. , Sigmund C. M. , Dors K. Martin
Published: July 2010

One‐half of a 35‐ by 250‐m riparian buffer cropped in corn (Zea mays L.) was seeded with fine leaf fescue (Festuca spp.) and allowed to remain idle to determine water quality changes resulting from riparian buffer restoration. A corn control was also used in this paired watershed design located in Connecticut. Water, N, and P fluxes were determined for precipitation, overland flow, and ground water. Also, an N mass balance was calculated. Total Kjeldahl nitrogen (TKN) and total phosphorus (TP) concentrations significantly (P < 0.05) increased as ground water flowed through the restored buffer. Nitrate N (NO3‐N) concentrations declined significantly but most (52%) of the decrease occurred within a 2.5‐m wetland adjacent to the stream. An N mass balance for the 2.5‐m strip indicated that denitrification only accounted for 1% of the N losses and plant uptake was from 7 to 13% of the N losses annually. Ground water was the dominant source of N to the buffer and also the dominant loss. Restoration of the riparian buffer decreased (p < 0.05) overland flow concentrations of TKN by 70%, NO3‐N by 83%, TP by 73%, and total suspended solids (TSS) by 92% as compared with the control. Restoration reduced (p < 0.05) NO3‐N concentrations in ground water by 35% as compared with the control. Underestimated denitrification and dilution by upwelling ground water in the wetland area adjacent to the stream were believed to be primarily responsible for the decreasing NO3‐N concentrations observed.
Effect of pH on Sorption and Transport of Fluorobenzoic Acid Ground Water Tracers
Authors: McCarthy John F. , Howard Kevin M. , McKay Larry D.
Published: July 2010

Sorption and transport behavior of fluorobenzoic acid (FBA) tracers were evaluated as ground water tracers in a highly weathered and fractured clay‐rich saprolite under both acidic and neutral conditions in laboratory batch tests and column transport studies. The FBAs are a group of 14 organic acids with pKa from 2.71 to 3.83, and may thus be potentially retarded in weathered, acidic soils. The degree of sorption was directly related to the pKa of the isomer and the pH of the solution. A technique for determining the intrinsic partitioning coefficient (Kd) of an non‐ionized species was derived to predict the equilibrium sorption of a family of compounds over a range of pH and pKa. For the diflourobenzoic acids used in this study, Kd was 2.50 L/kg. The intact column transport experiments confirmed that at neutral pH, none of the FBA isomers were retarded relative to a nonreactive tracer (Br−). Under acidic conditions (pH = 5.2), significant retardation was observed for isomers with higher pKa. Because the use of FBA tracers could be limited by regulatory concerns about potential toxic effects in surface water receiving discharge from ground water containing FBA, aquatic toxicity was assessed using a Ceriodaphnia 96‐h acute toxicity test. The LD50 (the concentration resulting in mortality of ≥50% of the test organisms) for the four FBA isomers tested was above 100 mg/L. The results of these equilibrium isotherm and column transport experiments demonstrate that FBAs can be very useful as nonreactive ground water tracers in these materials as long as the pH is approximately 2 pH units above the pKa (i.e., >99% ionized).
Nitrate Leaching and Nitrogen Budget as Affected by Maize Nitrogen Rate and Soil Type
Authors: Sogbedji Jean M. , van Es Harold M. , Yang Charissa L. , Geohring Larry D. , Magdoff Fred R.
Published: July 2010

Leaching loss as nitrate (NO3) is a growing concern because of its potential effect on water resources. Leaching of NO3 with drainage water from subsurface‐drained field plots seeded to maize (Zea mays L.) in 1992, 1993, and 1994 was measured on two soil types (a clay loam and a loamy sand) and for three N fertilization rates (22, 100, and 134 kg N ha−1). The 100 kg ha−1 rate was based on the results of a presidedress nitrate test (PSNT). Nitrate nitrogen (NO3‐N) leaching was similar between fertilizer N treatments at both sites in 1992, the first year after sod plowdown, but concentrations were greater than 10 mg L−1. For the subsequent two years, losses were similar for the 22 kg N ha−1 and the PSNT‐based treatments, but significantly higher for the 134 kg N ha−1 treatment on the clay loam. On the loamy sand, losses increased from the lowest to the highest N rate. Nitrate leaching losses were consistently higher on the loamy sand than on the clay loam. The N budget results showed that the 134 kg N ha−1 rate had the highest residual soil NO3‐N in the three years at both sites. On the clay loam, significant N losses occurred from denitrification following alfalfa plowdown and the subsequent fall and spring. Results indicate that N use efficiency rapidly decreases with overfertilization, even with N fertilization rates that only slightly exceed (134%) crop requirements. The PSNT‐based rate reduced N leaching losses while maintaining maize yields.
Molybdenum Content of Water Treatment Residuals
Authors: Elliott H. A. , Taylor M.
Published: July 2010

Molybdenum (Mo) content of water treatment residuals (WTRs) was determined by inductively coupled plasma atomic emission spectroscopy (ICP‐AES) to evaluate suitability for land application under state regulatory policies that limit Mo to 18 mg kg−1. Samples of WTR were collected from 32 Pennsylvania facilities that employ aluminum salts, ferric chloride, and/or polymers for coagulation. The mean Mo content of all samples was 3.1 mg kg−1, with 78% having Mo levels <5 mg kg−1. The WTRs from plants using ferric chloride as a coagulant averaged 5.6 mg Mo kg−1, significantly higher (p = 0.02) than the 1.6 mg Mo kg−1 for utilities using alum. Differences were related to coagulant purity: Mo content in liquid ferric chloride was 10.0 mg L−1 but below detection by ICP‐AES for alum. The initial sample from one facility, collected from the filter backwash basin, contained 26.4 mg Mo kg−1. Elevated Mo in backwash solids was attributed to filtration capture of extremely fine, Mo‐enriched AI hydrous oxide particles and erosion of anthracite filter media during backwashing. Combined backwash and coagulation solids from this facility's storage lagoon averaged 6.3 mg Mo kg−1, underscoring the need for consistent sampling procedures. The mean Cu to Mo ratio in these WTRs was >100, well above the minimum dietary ratio (2:1) considered protective of grazing animals.
Stability and Mobility of Napropamide Complexed with Dissolved Organic Matter in Soil Columns
Authors: Nelson S. D. , Farmer W. J. , Letey J. , Williams C. F.
Published: July 2010

The herbicide napropamide [N,N‐diethyl‐2‐(1‐naphthyloxy)propanamide] has been shown to complex with various sources of dissolved organic matter (DOM), potentially increasing the risk of ground water contamination by facilitating napropamide transport through soil. Two factors that may reduce the threat of facilitated transport of chemicals through soils are soil profile depth and soil horizon variability. Movement through the soil profile may cause herbicide complexed with DOM to break apart and readsorb to the soil. Differences in soil horizon organic matter content throughout the soil profile may also alter the potential for facilitated transport of herbicides. Napropamide was used in column studies to determine if organic matter differences in horizons and soil profile depth would reduce the risk of facilitated transport. A silt loam soil was used with and without sewage sludge amendment (SS and NoSS) to represent differences in organic matter content. Results showed that <6% of the applied mass of napropamide moved as DOM complexes through soil. The majority of complexed napropamide was very stable and relatively nonadsorbing in solution such that doubling of soil depth only reduced facilitated transport by 20% or less. We present evidence to show that napropamide‐DOM complexes are relatively nonadsorbing in solution and exhibit transport characteristics similar to those of a inert compounds in soil solution.
Predicting Solute Transport Using Mapping‐Unit Data: Model Simulations versus Observed Data at Four Field Sites
Authors: Macur Richard E. , Gaber Hesham M. , Wraith Jon M. , Inskeep William P.
Published: July 2010

Solute transport models may be used in conjunction with soils and climatic databases to predict the sensitivity of soil mapping units to leaching of agrichemicals. The primary objective of this study was to compare predicted solute transport obtained from several modeling approaches to observed data collected at four irrigated field sites throughout Montana. Observed solute distribution data as a function of soil depth was collected using Br− and a moderately sorbing herbicide, bromacil (5‐bromo‐3‐sec‐butyl‐6‐methyluracil), for three sampling dates over a period of 1 yr and used for evaluating different approaches for generating model predictions. The observed data were compared to predictions generated by two process‐based solute transport models, Chemical Movement in Layered Soils (CMLS) and Leaching Estimation and Chemistry Models (LEACHM), which differ in level of sophistication. Model predictions were obtained using inputs based on either detailed site characteristics (i.e., soil profile characterization) or the 1:24 000 scale USDA‐NRCS Soil Survey (SSURGO) database coupled with parameter estimation routines. Comparisons of observed and simulated transport showed that although LEACHM and CMLS frequently underestimated solute transport, both models performed similarly using either site‐specific inputs or SSURGO derived inputs. Model simulations using SSURGO soils data and 23 yr of historical climate data resulted in only slight variations in predictions of solute transport, suggesting that SSURGO inputs coupled with historic climate data provide a fairly robust approach for evaluating the sensitivity of mapping units to pesticide leaching out of the root zone.
Biodegradation Assessment of Woolscour Sludge and Fellmongery Sludge
Authors: Williamson W. M. , Greenfield L. G. , Beare M. H.
Published: July 2010

Sustainable land application of agricultural and industrial wastes requires an understanding of factors likely to limit waste decomposition and the release of plant‐available nitrogen. This paper describes the biodegradation of a woolscour sludge and a fellmongery sludge and suggests a biodegradation assessment strategy suitable for agricultural and industrial wastes. After 50 d of decomposition in microcosms, the woolscour sludge mineralized 18% of initial C and 9% of initial N, while the fellmongery sludge mineralized 37% of initial C and 53% of initial N. Net N mineralization from woolscour sludge was principally constrained by the recalcitrant behaviour of the wool fiber component, whereas elevated temperature (43°C) or anaerobic conditions constrained fellmongery sludge decomposition. Two negative consequences of soil amendment were identified. First, soil amended with fellmongery sludge leached up to 39% of applied sludge N as mineral N during 100 d of decomposition. Second, both sludges caused a reduction in microbial blomass (MB) after 1 yr of soil amendment. Our data indicated that the woolscour sludge was a substrate of low quality for soil microbial metabolism and that chemical parameters are a poor predictor of biodegradation. On the other hand, the fellmongery sludge was a substrate of moderately high quality for which chemical characteristics permitted relatively consistent prediction of N mineralization.
Denitrification Rates Predicted by Nitrogen‐15 Labeled Nitrate Microcosm Studies, In Situ Measurements, and Modeling
Authors: Hoffmann Carl Christian , Rysgaard Søren , Berg Peter
Published: July 2010

Denitrification rates in the range of 359 to 599 niniol N m−2 d−1 were found in the waterlogged soil of a minerotrophic fen. Three different methods were used to estimate denitrification rates. The fen revealed a zone of enhanced denitrification and within this zone the spatial variation of denitrification rates was elucidated using two different approaches: microcosms and field observations. The denitrification rates in the microcosms were measured, either by use of 15N‐N2 production rates (Method 1) or by setting up a mass balance for nitrate (Method 2). Denitrification rates in the peat horizon at depths of 0 to 69 cm were in the range 182 to 243 mmol N m−2 d−1 (Method 1) and 213 to 217 mmol N m−2 d−1 (Method 2). Denitrification rates measured in the deeper sandy soil horizons at depths of 69 to 156 cm were 46 to 103 mmol N m−2 d−1 (Method 1) and 33 to 137 mmol N m−2 d−1 (Method 2). Thus, both experiments revealed a strong and comparable decrease in denitrification rate with depth, which also corresponded well to soil carbon content. Denitrification rates were calcultaed from field data using Daicy's law and the conservation equation for one‐dimensional, steady state, advective transport of nitrate in an incompressible porous medium. The same significant decrease in denitrification rates with depth was observed as in the microcosm setup. The calculated denitrification rates were: 330 mmol N m−2 d−1 at depths of 0 to 75 cm (peat), 20 mmol N m−2 d−1 at depths of 75 to 115 cm (sandy soil), and 9 mmol N m−2 d−1 in the sandy soil horizon at depths of 155 to 205 cm. This study shows that detailed spatial information about pedological and hydrological parameters in combination with detailed spatial mapping and measurement of denitrification rates is fundamental for properly understanding nitrogen removal in waterlogged soils with ground water through‐flow. Further, the results confirm that provided this information is present, it is possible to compare detailed laboratory experiments with field studies of denitrification.
Selected Veterinary Pharmaceuticals in Agricultural Water and Soil from Land Application of Animal Manure
Authors: Song Wenlu , Ding Yunjie , Chiou Cary T. , Li Hui
Published: July 2010

Veterinary pharmaceuticals are commonly administered to animals for disease control, and added into feeds at subtherapeutic levels to improve feeding efficiency. As a result of these practices, a certain fraction of the pharmaceuticals are excreted into animal manures. Land application of these manures contaminates soils with the veterinary pharmaceuticals, which can subsequently lead to contamination of surface and groundwaters. Information on the occurrence and fate of pharmaceuticals in soil and water is needed to assess the potential for exposure of at‐risk populations and the impacts on agricultural ecosystems. In this study, we investigated the occurrence and fate of four commonly used veterinary pharmaceuticals (amprolium, carbadox, monensin, and tylosin) in a farm in Michigan. Amprolium and monensin were frequently detected in nearby surface water, with concentrations ranging from several to hundreds of nanograms per liter, whereas tylosin or carbadox was rarely found. These pharmaceuticals were more frequently detected in surface runoff during nongrowing season (October to April) than during growing season (May to September). Pharmaceuticals resulting from postharvest manure application appeared to be more persistent than those from spring application. High concentrations of pharmaceuticals in soils were generally observed at the sites where the respective concentrations in surface water were also high. For monensin, the ratios of soil‐sorbed to aqueous concentrations obtained from field samples were within the order of the distribution coefficients obtained from laboratory studies. These results suggest that soil is a reservoir for veterinary pharmaceuticals that can be disseminated to nearby surface water via desorption from soil, surface runoff, and soil erosion.
Sources and Distribution of Organic Compounds Using Passive Samplers in Lake Mead National Recreation Area, Nevada and Arizona, and Their Implications for Potential Effects on Aquatic Biota
Authors: Rosen Michael R. , Alvarez David A. , Goodbred Steven L. , Leiker Thomas J. , Patiño Reynaldo
Published: July 2010

The delineation of lateral and vertical gradients of organic contaminants in lakes is hampered by low concentrations and nondetection of many organic compounds in water. Passive samplers (semipermeable membrane devices [SPMDs] and polar organic chemical integrative samplers [POCIS]) are well suited for assessing gradients because they can detect synthetic organic compounds (SOCs) at pg L−1 concentrations. Semi‐permeable membrane devices and POCIS were deployed in Lake Mead, at two sites in Las Vegas Wash, at four sites across Lake Mead, and in the Colorado River downstream from Hoover Dam. Concentrations of hydrophobic SOCs were highest in Las Vegas Wash downstream from waste water and urban inputs and at 8 m depth in Las Vegas Bay (LVB) where Las Vegas Wash enters Lake Mead. The distribution of hydrophobic SOCs showed a lateral distribution across 10 km of Lake Mead from LVB to Boulder Basin. To assess possible vertical gradients of SOCs, SPMDs were deployed at 4‐m intervals in 18 m of water in LVB. Fragrances and legacy SOCs were found at the greatest concentrations at the deepest depth. The vertical gradient of SOCs indicated that contaminants were generally confined to within 6 m of the lake bottom during the deployment interval. The high SOC concentrations, warmer water temperatures, and higher total dissolved solids concentrations at depth are indicative of a plume of Las Vegas Wash water moving along the lake bottom. The lateral and vertical distribution of SOCs is discussed in the context of other studies that have shown impaired health of fish exposed to SOCs.
Sediment Fingerprinting to Determine the Source of Suspended Sediment in a Southern Piedmont Stream
Authors: Mukundan R. , Radcliffe D. E. , Ritchie J. C. , Risse L. M. , McKinley R. A.
Published: July 2010

Thousands of stream miles in the southern Piedmont region are impaired because of high levels of suspended sediment. It is unclear if the source is upland erosion from agricultural sources or bank erosion of historic sediment deposited in the flood plains between 1830 and 1930 when cotton farming was extensive. The objective of this study was to determine the source of high stream suspended sediment concentrations in a typical southern Piedmont watershed using sediment fingerprinting techniques. Twenty‐one potential tracers were tested for their ability to discriminate between sources, conservative behavior, and lack of redundancy. Tracer concentrations were determined in potential sediment sources (forests, pastures, row crop fields, stream banks, and unpaved roads and construction sites), and suspended sediment samples collected from the stream and analyzed using mixing models. Results indicated that 137Cs and 15N were the best tracers to discriminate potential sediment sources in this watershed. The δ15N values showed distinct signatures in all the potential suspended sediment sources, and δ15N was a unique tracer to differentiate stream bank soil from upland subsurface soils, such as soil from construction sites, unpaved roads, ditches, and field gullies. Mixing models showed that about 60% of the stream suspended sediment originated from eroding stream banks, 23 to 30% from upland subsoil sources (e.g., construction sites and unpaved roads), and about 10 to 15% from pastures. The results may be applicable to other watersheds in the Piedmont depending on the extent of urbanization occurring in these watersheds. Better understanding of the sources of fine sediment has practical implications on the type of sediment control measures to be adopted. Investment of resources in improving water quality should consider the factors causing stream bank erosion and erosion from unpaved roads and construction sites to water quality impairment.
Order of Functionality Loss during Photodegradation of Aquatic Humic Substances
Authors: Thorn Kevin A. , Younger Steven J. , Cox Larry G.
Published: July 2010

The time course photodegradation of the Nordic aquatic fulvic and humic acids and Suwannee River XAD‐4 acids subjected to UV irradiation with an unfiltered medium pressure mercury lamp was studied by liquid‐state 13C nuclear magnetic resonance. Photodecarboxylation was a significant pathway in all cases. Decreases in ketone, aromatic, and O‐alkyl carbons were observed throughout the course of the irradiations, whereas C‐alkyl carbons resisted photodegradation. Peaks attributable to the low‐molecular‐weight photodegradation products bicarbonate, formate, acetate, and succinate grew in intensity with irradiation time. The final products of the irradiations were decarboxylated, hydrophobic, predominantly C‐alkyl and O‐alkyl materials that were resistant to further photodegradation. The total amount of carbon susceptible to loss appeared to be related mainly to the total concentration of carbonyl and aromatic carbons and partly to the concentration of O‐alkyl carbons in the fulvic, humic, and XAD‐4 acids. The carbon losses for Nordic fulvic, Nordic Humic, Suwannee fulvic, and Suwannee XAD‐4 acids were estimated to be 75, 63, 56, and 17%, respectively. More detailed analyses of the effects of irradiation on the carbonyl functionality in Nordic humic acid and Laurentian soil fulvic acid through reaction with hydroxylamine in conjunction with 15N nuclear magnetic resonance analysis confirmed preferential photodegradation of the quinone/hydroquinone functionality over ketone groups and the loss of ester groups in Laurentian fulvic acid.
A Simple Metric to Predict Stream Water Quality from Storm Runoff in an Urban Watershed
Authors: Easton Zachary M. , Sullivan Patrick J. , Walter M. Todd , Fuka Daniel R. , Petrovic A. Martin , Steenhuis Tammo S.
Published: July 2010

The contribution of runoff from various land uses to stream channels in a watershed is often speculated and used to underpin many model predictions. However, these contributions, often based on little or no measurements in the watershed, fail to appropriately consider the influence of the hydrologic location of a particular landscape unit in relation to the stream network. A simple model was developed to predict storm runoff and the phosphorus (P) status of a perennial stream in an urban watershed in New York State using the covariance structure of runoff from different landscape units in the watershed to predict runoff in time. One hundred and twenty‐seven storm events were divided into parameterization (n = 85) and forecasting (n = 42) data sets. Runoff, dissolved P (DP), and total P (TP) were measured at nine sites distributed among three land uses (high maintenance, unmaintained, wooded), three positions in the watershed (near the outlet, midwatershed, upper watershed), and in the stream at the watershed outlet. The autocorrelation among runoff and P concentrations from the watershed landscape units (n = 9) and the covariance between measurements from the landscape units and measurements from the stream were calculated and used to predict the stream response. Models, validated using leave‐one‐out cross‐validation and a forecasting method, were able to correctly capture temporal trends in streamflow and stream P chemistry (Nash–Sutcliffe efficiencies, 0.49–0.88). The analysis suggests that the covariance structure was consistent for all models, indicating that the physical processes governing runoff and P loss from these landscape units were stationary in time and that landscapes located in hydraulically active areas have a direct hydraulic link to the stream. This methodology provides insight into the impact of various urban landscape units on stream water quantity and quality.
Correlation for Prediction of Minimum Fluidization Velocity and Riser Liquid Holdup in Three-Phase External Loop Air Lift Fluidized Bed Reactor
Authors: Venkatachalam Sivakumar , Kandasamy Kannan , Kandasamy Senthilkumar
Published: July 2010

The effect of superficial gas and liquid velocities and properties of solids on the minimum fluidization velocity and riser liquid holdup of a three-phase external loop air lift fluidized bed reactor was characterized using Newtonian and non-Newtonian systems. Water, 65% and 85% of glycerol and n-Butanol were used as Newtonian liquids and different concentrations of carboxymethyl cellulose (i.e. 0.2%, 0.5% and 1% CMC) were used as non-Newtonian liquids. Spherical glass beads, bearl saddles and rasching rings of different sizes were used as solid phases. The phase flow rates and properties of solid particles had significant effects on the hydrodynamic characteristics of the external loop air lift fluidized bed reactor, such as minimum fluidization velocity and riser liquid holdup. Unified correlations have been developed to estimate the minimum fluidization velocity and riser liquid holdup as a function of superficial phase velocities, properties of solid particles and physical properties of both Newtonian and non-Newtonian liquid systems. The predicting ability of the correlations were tested with the experimental data and found to be a good fit with an absolute average relative deviation (AARD) of ± 6.5 % and ± 7.8 % for minimum fluidization velocity and riser liquid holdup, respectively.
Ecological Optimization of Generalized Irreversible Chemical Engines
Authors: Chen Lingen , Xia Dan , Sun Fengrui
Published: July 2010

Optimal ecological performance of generalized irreversible chemical engine cycles with both linear and diffusive mass transfer laws are derived by taking an ecological optimization criterion as the objective, which consists of maximizing a function representing the best compromise between the power output and the entropy production rate of the chemical engines. In this paper, the relations between the ecological function, power output, entropy production rate and the efficiency of a chemical engine cycle with irreversibilities of mass transfer, mass leakage and internal dissipation, in which the mass transfer, are derived. This paper also derives the maximum ecological function and the corresponding power output, entropy production rate and efficiency, the maximum power output and the corresponding ecological function, entropy production rate and efficiency, and the maximum efficiency and the corresponding ecological function, power output and entropy production rate. The results can provide some theoretical guidelines for the design of practical chemical engines.
Improvising the Document
Authors: Ferguson Alex Lazaridis
Published: July 2010

In a documentary play in which actors represent living or historical people, textual artefact is replaced by creatively embodied document. Every stage of the construction of that document, from a subject's recall of events, to a researcher's transcription of the subject's testimony, to performance, is an act of improvisation. Reflecting on Nanay: a testimonial play, this paper examines the document as a necessarily creative construction. It describes improvisative decisions made at every stage of the rehearsal process, how they resulted in naturalistic or non-naturalistic staging, and how spectators and researchers correlated truth claims to the various theatrical genres employed. Referencing cognitive and event theories, Ferguson argues that the spectator engages with embodied performance somatically, and that “identification” based on mutual embodied encounter becomes critical to the spectator's acceptance or rejection of a documentary play's truth claims.
Improvising In and Out of the Box
Authors: Koo Camellia
Published: July 2010

Improvisation plays a significant role in almost all aspects of my process as a designer, from staying open to possibilities and surprises that emerge during discussions with directors and other collaborators and even while I am building a maquette, to being a designer in the room during dramaturgical and production workshops, to using improvisation as a tool when instigating my own performance installations. My personal interest and development as an artist involves the pursuit of finding new methods of creating and designing during the process of theatremaking and inherently relies on my ability to improvise with collaborators.
Theatre of the Unexpected: When the Spectator Becomes Actor
Authors: Guay Louis-Martin , Dinsmore Jacqueline
Published: July 2010

Improvisation has held an important place in the world of interactive theatrical expression for almost fifty years now. Situated halfway between theatrical performance and party game, this form of dramatic expression is considered by many as almost-theatre. It involves protagonists who interpret their roles in a highly interactive activity that fluctuates between reality and fiction. In keeping with Augusto Boal's seminal theatrical model, a spontaneous process emerges that blurs the distinction between actor and spectator as they become true participants in a game. From Artaud to Caillois, we can retrace the genesis of a spontaneous hybrid form of game. Presented in Montreal in 2009, the spectacle Open House will be used as a subject of study and analysis to conduct thorough research on this activity. This article will put into perspective the notions of games and player/actors using a form of theatrical activity that we can define as “Theatre of the Unexpected.”
Sandpaper: The Story of Moncton-Sable
Authors: Collette Philip André
Published: July 2010

“Sandpaper: The Story of Moncton-Sable” traces the outlines of Le Collectif Moncton-Sable starting with its conception by founder Louise Lemieux “to experiment with creating productions using the set design as the starting and focal point of the process.” The company members, the core of whom have returned production after production, come from various artistic backgrounds but share the goal of creating theatre through “freely exploring ideas, themes, and stories inspired by a raw material and generated through physical improvisation linked to that material.” This article focuses on the 2006 tenth-anniversary production entitled Papier, which was the company's largest undertaking, involving upwards of twenty collaborators including actors, musicians, designers, and writers. The production combined the company's physical, improvisation-based techniques with more text-based approaches they had experimented with occasionally. Today the company continues its interest in laboratory, experimental workshops, while developing more substantial productions.
Autism Fiction: A Mirror of an Internet Decade?
Authors: Hacking Ian
Published: July 2010

In the past decade there has been an extraordinary explosion of literature – both fiction and non-fiction – in which autism plays a key role. This paper surveys the very diverse genre that has resulted and examines some of its effects on the evolution of our understanding of autism and on our ability to talk about autistic experience. It also notes the role of the Internet in enabling autistic people to interact with others while avoiding the difficulties of face-to-face interaction. It proposes that the public fascination with autistic texts mirrors the dominance of the Internet in daily life. Both such texts and the Internet itself represent radical changes in the horizon of communication.
If ‘The Body Keeps the Score’: Mapping the Dissociated Body in Trauma Narrative, Intervention, and Theory
Authors: Crawford Allison
Published: July 2010

Psychotherapy, a central social space for remembering, has from its inception centred upon the healing and integrative power of putting experience into words and narrative forms of expression. However, those who have experienced traumatic events often lack a coherent memory for or understanding about the trauma they have undergone; they may be haunted by inchoate bodily sensations and ‘memories’ that have not been fully integrated and cannot be put into language. Such splits in experience – between body and mind – can provide a means to understand the way we conceptualize memory, consciousness, and body-mind. This paper describes an intervention that seeks to help people to make the experiences of the body more intelligible.
How to Make Up One's Mind: Reason, Passion, and Ethics in Spirit Possession
Authors: Lambek Michael
Published: July 2010

What does it mean to know one's own mind, to make up one's mind, or to be of two minds? The paper explores some of the assumptions Westerners make about mind and confronts them with elements from the ethnography of spirit possession among Malagasy speakers. It challenges the assumption that a unified state of mind, exemplified by pure reason as opposed to passion, is the necessary basis for sound ethical judgment and action.
Bridging the Past and the Future: Rethinking the Temporal Assumptions of Trauma Theory in Dionne Brand'sAt the Full and Change of the Moon
Authors: Grandison Julia
Published: July 2010

As an account of the descendants of a woman who is enslaved, tortured, and driven to assist a mass suicide in nineteenth-century Trinidad, Dionne Brand's At the Full and Change of the Moon represents the intergenerational effects of traumatic experience. In accordance with the writings of theorists such as Cathy Caruth or Nicholas Abraham, who emphasize the disruptive – even trans-generational – persistence of traumatic events, this novel traces the haunting recurrence of images or sentiments associated with traumatic experience across generations. However, while some trauma theorists focus on the disruptiveness of traumatic memory when it recurs in the present, Brand's novel represents moments accompanying traumatic memories as pauses in time during which characters exercise agency. I argue that even when Brand's characters seem to be seized by the past, they also, often very subtly, evoke the future. Consequently, Brand's text supports the work of Ruth Leys, E. Ann Kaplan, and Richard McNally, which recognizes the role of psychic agency in accessing and responding to traumatic memory.
Emotions and Eating Behaviour: Implications for the Current Obesity Epidemic
Authors: Levitan Robert D. , Davis Caroline
Published: July 2010

Developed countries around the world are experiencing an epidemic of overeating and obesity with significant costs at a personal, familial, and societal level. While most research on obesity has focused on metabolic factors, this paper considers how emotional factors might contribute to this problem. Two examples we address are the use of food to modify negative mood states, also called emotional eating, and food intake as an addiction. Our central question is what makes some individuals prone to emotional eating and/or food addiction, while others are clearly less vulnerable in this regard. Ultimately, we suggest how obesity research, prevention, and treatment might address the emotional underpinnings of the current overeating epidemic.
Tears of Joy: Hollywood Melodrama, Ecstasy, and Restoring Meta-Narratives of Transcendence in Modernity
Authors: Leonard Garry
Published: July 2010

There is critical consensus that modernity is characterized by a lack of meta-narratives, by de-sacralization, by the sequestration of people from the meaning contained in their life experiences, and by a crisis in valuation. This paper argues that Hollywood melodrama compensates for these aspects of modern life by locating the sacred within the secular. Part of the compensatory function served by this genre is effected through the emotional impact that melodramas have on audiences, which can be usefully contextualized in relation to religious ecstasy. A comparative analysis of the two films Broken Blossoms (1919) and American Beauty (1999) reveals how the evocation of ecstasy through film can reinstate meta-narratives, present an alternative means of valuation to capitalism, and manifest an opposite logic to that of investment – that of sacrifice.
Crystallisation of Wild-Type and Variant Forms of a Recombinant Plant Enzyme β-D-Glucan Glucohydrolase from Barley (Hordeum vulgare L.) and Preliminary X-ray Analysis
Authors: Luang Sukanya , Cairns James R. Ketudat , Streltsov Victor A. , Hrmova Maria
Published: July 2010

Wild-type and variant crystals of a recombinant enzyme β-d-glucan glucohydrolase from barley (Hordeum vulgare L.) were obtained by macroseeding and cross-seeding with microcrystals obtained from native plant protein. Crystals grew to dimensions of up to 500 x 250 x 375 µm at 277 K in the hanging-drops by vapour-diffusion. Further, the conditions are described that yielded the wild-type crystals with dimensions of 80 x 40 x 60 µm by self-nucleation vapour-diffusion in sitting-drops at 281 K. The wild-type and recombinant crystals prepared by seeding techniques achieved full size within 5-14 days, while the wild-type crystals grown by self-nucleation appeared after 30 days and reached their maximum size after another two months. Both the wild-type and recombinant variant crystals, the latter altered in the key catalytic and substrate-binding residues Glu220, Trp434 and Arg158/Glu161 belonged to the P43212 tetragonal space group, i.e., the space group of the native microcrystals was retained in the newly grown recombinant crystals. The crystals diffracted beyond 1.57-1.95 Å and the cell dimensions were between a = b = 99.2-100.8 Å and c = 183.2-183.6 Å. With one molecule in the asymmetric unit, the calculated Matthews coefficients were between 3.4-3.5 Å3.Da-1 and the solvent contents varied between 63.4% and 64.5%. The macroseeding and cross-seeding techniques are advantageous, where a limited amount of variant proteins precludes screening of crystallisation conditions, or where variant proteins could not be crystallized.
Multiple Beneficial Health Effects of Natural Alkylglycerols from Shark Liver Oil
Authors: Deniau Anne-Laure , Mosset Paul , Pédrono Frédérique , Mitre Romain , Bot Damien Le , Legrand Alain B.
Published: July 2010

Alkylglycerols (alkyl-Gro) are ether lipids abundant in the liver of some elasmobranch fish species such as ratfishes and some sharks. Shark liver oil from Centrophorus squamosus (SLO), or alkyl-Gro mix from this source, have several in vivo biological activities including stimulation of hematopoiesis and immunological defences, sperm quality improvement, or anti-tumor and anti-metastasis activities. Several mechanisms are suggested for these multiple activities, resulting from incorporation of alkyl-Gro into membrane phospholipids, and lipid signaling interactions. Natural alkyl-Gro mix from SLO contains several alkyl-Gro, varying by chain length and unsaturation. Six prominent constituents of natural alkyl-Gro mix, namely 12:0, 14:0, 16:0, 18:0, 16:1 n-7, and 18:1 n-9 alkyl-Gro, were synthesized and tested for anti-tumor and anti-metastatic activities on a model of grafted tumor in mice (3LL cells). 16:1 and 18:1 alkyl-Gro showed strong activity in reducing lung metastasis number, while saturated alkyl-Gro had weaker (16:0) or no (12:0, 14:0, 18:0) effect. Multiple compounds and mechanisms are probably involved in the multiple activities of natural alkyl-Gro.
Intervention Effects in the Case of Heterogeneity between Three Subgroups
Authors: Bender R. , Skipka G.
Published: July 2010

Background: Usually, statistical tests for interactions are applied to investigate potential effect modifiers. If an effect modifier, consisting of three categories, is found to be statistically significant, the application of pairwise interaction tests is indicated. In this case, the problem of non-transitive relations may occur if the significance level is fixed at 0.05 for all tests.

Objective: To develop an algorithm for which non-transitive relations do not occur.

Methods: A hierarchical testing procedure is applied, based on the heterogeneity statistic Q. In a first step the interaction will be tested for the three trial subgroups altogether, applying the significance level α = 0.05 (global test). If a significant interaction is proven in the first step, pairwise tests for interaction will be applied in a second step. Theoretical data scenarios will be considered and p-values will be calculated for the pairwise tests. Based on these results the significance level for pairwise testing will be determined.

Results: Fixing the significance level at 0.05 for all tests, the problem of non-transitive relations is mostly relevant, if the difference in the effects between the three trial subgroups is approximately 3.5 standard errors and the effect of the ‘middle’ trial subgroup is not close to one of the other two effects. This problem vanishes when the significance level is set to α = 0.22. We propose to select α = 0.20 to get a more ’even’ and simple value.

Conclusions: By increasing the significance level for the pairwise tests to 0.20, non-transitive relations are virtually avoidable. The proposed hierarchical testing procedure represents a clear practical guidance to perform subgroup analyses in the framework of systematic reviews.
2 N POSITIVE PERIODIC SOLUTIONS TO N SPECIES NON‐AUTONOMOUS LOTKA‐VOLTERRA UNIDIRECTIONAL FOOD CHAINS WITH HARVESTING TERMS
Authors: Li Yongkun , Zhao Kaihong
Published: July 2010

By using the Mawhin continuation theorem of coincidence degree theory and some results on inequalities, we establish the existence of 2 n positive periodic solutions for n species non‐autonomous Lotka‐Volterra unidirectional food chains with harvesting terms. Two examples are given to illustrate the effectiveness of our results.
Primary Stenting Immediatly after Surgery in Occluded Anastomoses of Aortoaortic Tube Graft: A Case Report
Authors: Rabellino M. , García-Nielsen L. , Zander T. , Baldi S. , Estigarribia A. , Zerolo I. , Cheves H. , Llorens R. , Maynar M.
Published: July 2010

The conventional elective open procedures for abdominal aortic aneurysm repair are reliable and yield durable results. The aortoaortic tube graft has the lowest morbidity incidence when compared with different techniques. Albeit infrequent, thrombosis can be present in the first 30 days. Its treatment consists in thrombectomy and anastomosis evaluation, but with an increase in morbidity, especially in patients with urgent reintervention. This is a case report of a patient with aortoaortic tube graft, who present critical left limb ischemia immediately after surgical procedure. Angiography showed complete occlusion of left common iliac artery, affecting the distal graft anastomosis. The occlusion was resolved with endovascular treatment, and a noncovered, self-expanding, nitinol stent was deployed (primary stenting) covering the distal bypass anastomosis, with no complications and complete lower limb perfusion recovery. One month later, the patient was still asymptomatic, with distal pulse palpable and ankle-brachial index 1.