bluuebunny/crossref_metadata_2025 huggingface dataset:
Fabrication of SmCo5 Alloy Magnetic Nanoparticles by Assistance of Copper and Their Magnetic Properties
Authors: Tokonami Shiho , Kinjo Mutsuko , Inokuchi Makoto , Toshima Naoki
Published: June 2009

SmCo5 magnetic nanoparticles were preparaed through a simultaneous reduction of Sm(acac)3·xH2O and Co(acac)3 by assistance of Cu(acac)2 and NaBH4 in the presence of oleic acid and oleylamine as a protectant. Supplementation of Cu activated the formation of SmCo5 nanoparticles having a CaCu5 structure, and use of NaBH4 as a reducing agent played an important role to prevent samarium and cobalt from oxidation during preparation. The mean particle diameter was 3.4 nm, having a well-controlled crystal morphology. The magnetic properties of the prepared nanoparticles represented sufficiently high coercivity and magnetization of 1300 Oe and 15.7 emu g−1, respectively, at room temperature.
Photoinduced Outgrowth of Gold Nanotadpoles in Aqueous Bilayer Dispersions
Authors: Soejima Tetsuro , Hasegawa Toshio , Morikawa Masa-aki , Kimizuka Nobuo
Published: June 2009

An aqueous-phase synthesis of gold nanotadpoles by using bilayer membranes as growth regulating factor is newly developed. The gold nanotadpoles are formed by photoreduction of Au(OH)4− in aqueous bilayer dispersion. The outgrowth of tails occurred from spherical nanoparticles, which are regulated depending on the photoirradiation time.
Single-Molecule Imaging of a Micro-Brownian Motion of a Chiral Helical π-Conjugated Polymer as a Molecular Spring Driven by Thermal Fluctuations
Authors: Shinohara Ken-ichi , Kodera Noriyuki , Ando Toshio
Published: June 2009

We observed a micro-Brownian motion of single molecules of a chiral helical π-conjugated polymer as a molecular spring on mica substrate under n-octylbenzene at room temperature using high-speed (rapid scan) AFM. The average velocity at the chain end of the polymer was 67 nm s−1 at the observation point. The analytical result shows that the mean square displacement in a single polymer chain is proportional to the time and, hence, complies with Einstein’s law of Brownian motion. The diffusion constant (D) is measured to be 8.2×10−15 m2 s−1 at the solid/liquid interface.
The Association Between Maternal Anxiety and Treatment Outcome for Childhood Anxiety Disorders
Authors: Gar Natalie S. , Hudson Jennifer L.
Published: June 2009

This study examined the influence of maternal anxiety on the treatment outcome of anxious children. Forty-eight clinically anxious children (aged 6–14 years) were classified into two groups based on the presence of an anxiety disorder diagnosis in their mother. Diagnostic data at posttreatment showed that children with anxious mothers responded significantly less favourably to cognitive behavioural therapy (CBT) than did children with nonanxious mothers (28% vs. 58% improved, respectively). At 12-month follow-up, 68% of children with anxious mothers improved, compared to 79% of children with nonanxious mothers. This difference was not significant. Findings were not consistent across outcome measures. This study also investigated the changes in maternal anxiety across child treatment. Prior to treatment, diagnostic data showed that 60% of mothers met criteria for an anxiety disorder. At posttreatment, 21% of these mothers were free of their primary diagnosis. There was also a significant reduction in self-reported maternal anxiety across treatment that was maintained at follow-up. Theoretical and clinical implications of the findings are discussed.
Dilatometric Analysis to Study Aging of Aluminum Alloys
Authors: Gerosa R. , Rivolta B. , Derudi U.
Published: June 2009

The microstructural modifications occurring during the natural or artificial aging of the aluminum alloys are related to modifications of physical properties such as electrical conductivity, hardness, and volume, each of them measured by specific instruments. In this paper the dimensional changes during the aging time were investigated through a high precision dilatometer; this technique keeps the sample at constant temperature and follows the precipitation phenomena versus time continuously. All the samples were taken from commercial thick plates of different aluminum alloys. The heavy plastic deformation during rolling was responsible for introducing anisotropy into the plate, so that the samples for the investigation were taken in the longitudinal, long transverse, and short transverse directions. By analyzing the dimensional changes of the samples versus aging time, standard and non-standard time-temperature values were selected as aging parameters for samples designated for mechanical and intergranular corrosion tests. The results obtained showed that the dilatometer can give important information about the precipitation kinetics occurring during aging, and it can be considered a useful instrumentation for the optimization of aging of aluminum alloys.
Chemical Speciation and Heavy Metal Mobility in Contaminated Marine Sediments
Authors: Damikouka Ioanna , Katsiri Alexandra
Published: June 2009

Management of sediments from coastal areas, contaminated with heavy metals and organic substances, is a very critical issue. Management decisions are usually based on total pollutant concentrations and various guidelines that are used by different countries. Heavy metals can be mobilized from polluted sediments if they are exposed to changing environmental conditions that occur during excavation, disposal at sea, or disposal in confined facilities. This paper examines the changes in heavy metals partitioning to binding phases in contaminated marine sediments and the release of metals to the environment. Environmental conditions are simulated by submitting sediments to a modified elutriation test with oxygenated and deoxygenated seawater. A sequential extraction procedure is used to determine the binding fractions of heavy metals in the sediments. Fractionation analysis of excavated marine sediments from the port of Piraeus, Greece showed that copper is primarily associated with organic matter, whereas lead and zinc are primarily associated with iron oxides. Under anoxic conditions, the metals bound to the various binding fractions remain practically stable. On the other hand, under oxic conditions, an increase in the concentration of metals associated with carbonates and a decrease in the concentration of metals associated with organic matter and iron oxides were observed. Both under oxic and anoxic conditions, actual metal mobility was very low and less than 0.5 % of total metal mass was found in the dissolved phase.
Comparative aspects of implantation
Authors: Bazer Fuller W , Spencer Thomas E , Johnson Greg A , Burghardt Robert C , Wu Guoyao
Published: June 2009

Uterine receptivity to implantation of blastocysts in mammals includes hatching from zona pellucida, precontact with uterine luminal (LE) and superficial glandular (sGE) epithelia and orientation of blastocyst, apposition between trophectoderm and uterine LE and sGE, adhesion of trophectoderm to uterine LE/sGE, and, in some species, limited or extensive invasion into the endometrial stroma and induction of decidualization of stromal cells. These peri-implantation events are prerequisites for pregnancy recognition signaling, implantation, and placentation required for fetal–placental growth and development through the remainder of pregnancy. Although there is a range of strategies for implantation in mammals, a common feature is the requirement for progesterone (P4) to downregulate expression of its receptors in uterine epithelia and P4prior to implantation events. P4then mediates its effects via growth factors expressed by stromal cells in most species; however, uterine luminal epithelium may express a growth factor in response to P4and/or estrogens in species with a true epitheliochorial placenta. There is also compelling evidence that uterine receptivity to implantation involves temporal and cell-specific expression of interferon (IFN)-stimulated genes that may be induced directly by an IFN or induced by P4and stimulated by an IFN. These genes have many roles including nutrient transport, cellular remodeling, angiogenesis and relaxation of vascular tissues, cell proliferation and migration, establishment of an antiviral state, and protection of conceptus tissues from challenges by the maternal immune cells.
In the Beginning Was the Worm …
Authors: Brenner Sydney
Published: June 2009

In my end is my beginning.

T. S. Eliot
Infant mortality trends in the State of Rio Grande do Sul, Brazil, 1994-2004: a multilevel analysis of individual and community risk factors
Authors: Zanini Roselaine Ruviaro , Moraes Anaelena Bragança de , Giugliani Elsa Regina Justo , Riboldi João
Published: June 2009

The aim of this study was to analyze the trend in infant mortality rates in the State of Rio Grande do Sul, Brazil, from 1994 to 2004, in a longitudinal ecological study, by means of panel data analysis and multilevel linear regression (two levels: microregion and time) to estimate factors associated with infant mortality. The infant mortality rate decreased from 19.2‰ (1994) to 13.7‰ (2004) live births, and the principal causes of death in the last five years were perinatal conditions (54.1%). Approximately 47% of the variation in mortality occurred in the microregions, and a 10% increase in coverage by the Family Health Program was associated with a 1‰ reduction in infant mortality. A 10% increase in the poverty rate was associated with a 2.1‰ increase in infant deaths. Infant mortality was positively associated with the proportion of low birthweight newborns and the number of hospital beds per thousand inhabitants and negatively associated with the cesarean rate and number of hospitals per 100 thousand inhabitants. The findings suggest that individual and community variables display significant effects on the reduction of infant mortality rates.
Experimental investigation of infiltration ponding in one-dimensional sand–geotextile columns
Authors: Bathurst R. J. , Siemens G. , Ho A. F.
Published: June 2009

The paper describes the results of laboratory tests that were carried out to quantify the geotextile water characteristic curves of a woven and nonwoven geotextile in new and modified conditions. The geotextiles were modified by contamination with kaolin powder. The specimens were placed in 2 m high, one-dimensional sand columns and subjected to constant head water infiltration loading. Conductivity probes and tensiometers were used to record the unsaturated–saturated response of the sand–geotextile layers and a control column with sand only. The test results showed a detectable delay in infiltration front advancement and ponding level, which increased with decreasing saturated permeability of the geotextile specimen. The use of geotextile– water characteristic curves from in-air laboratory suction plate tests is shown to underestimate water ponding heights in the columns, which means that their use for design may be nonconservative. Another practical implication of the work reported here is that for geotextile–sand systems under surface water infiltration loading, current filtration design criteria that call for the ratio of saturated hydraulic (conductivity) permeability of the geotextile to that of the surrounding sand be at least one, may need to be strengthened. For ratios of 1 and 10, the estimated ponding height above the geotextile was estimated to be 4 and 0.1 cm, respectively. Hence, ratios of saturated hydraulic permeability greater than one may be necessary to prevent lateral flow of water above a geotextile in sand fills used in wall, slope and road applications.
The performance of an embankment on soft ground reinforced with geosynthetics and pile walls
Authors: Zheng J. J. , Chen B. G. , Lu Y. E. , Abusharar S. W. , Yin J. H.
Published: June 2009

The construction of high embankments on soft ground faces several challenges, such as potential bearing capacity failure, global slope instability, local failure, large total and/or differential settlements, and large lateral movement during both construction and post-construction periods. Horizontal geosynthetic reinforcement combined with vertical reinforcement using piles or pile walls can provide an economical and effective solution to ground improvement to support high embankments. This paper reports the results of a numerical study on the performance of embankments on soft ground with three different reinforcement conditions: (1) unreinforced, (2) reinforced with geosynthetics, (3) reinforced with both geosynthetics and pile walls. The influencing factors, such as the tensile stiffness of the geosynthetic, the number of geosynthetic layers, the elastic modulus of the pile wall, and the pile wall distance ratio, on the interaction of geosynthetic-pile wall-soil systems were investigated and the distribution and dissipation of excess pore water pressure in the soil were examined. The numerical results show that a combination of geosynthetic reinforcement and the pile walls was very effective for the improvement of soft ground. The numerical results were shown to be in good agreement with the field data observed at the end of consolidation.
Seismic reliability assessment of external stability of reinforced soil walls using pseudo-dynamic method
Authors: Basha B. M. , Babu G. L. S.
Published: June 2009

The paper presents a method for the evaluation of external stability of reinforced soil walls subjected to earthquakes in the framework of the pseudo-dynamic method. The seismic reliability of the wall is evaluated by considering the different possible failure modes such as sliding along the base, overturning about the toe point of the wall, bearing capacity and the eccentricity of the resultant force. The analysis is performed considering properties of the reinforced backfill, foundation soil below the base of the wall, length of the geosynthetic reinforcement and characteristics of earthquake ground motions such as shear wave and primary wave velocity as random variables. The optimum length of reinforcement needed to maintain stability against four modes of failure by targeting various component reliability indices is obtained. Differences between pseudo-static and pseudo-dynamic methods are clearly highlighted in the paper. A complete analysis of pseudo-static and pseudo-dynamic methodologies shows that the pseudo-dynamic method results in realistic design values for the length of geosynthetic reinforcement under earthquake conditions.
Effects on Time-lapse Seismic of a Hard Rock Layer beneath a Compacting Reservoir
Authors: Tempone P. , Landrø M. , Fjær E. , Inoue N.
Published: June 2009

Geertsma's analytical method is often used to estimate changes in stress and strain in the rock around compacting reservoirs, and then to estimate seismic traveltime shifts. The present work extends Geertsma's analytical solution to the case where a hard rock layer is located beneath the compacting reservoir. The analytical solution for the three components of displacement has been derived using both thermo-elastic and poro-elastic theory. The impact of the hard rock layer on the seismic traveltime shifts are estimated by applying the dilation factor method for strain sensitivity of the seismic velocity, and then comparing the results for our model (Rigid Basement Model) to the results for the original Geertsma model.

The rigid layer prevents any displacements below a given depth below the reservoir. This has consequences for the displacements above the rigid layer. In our model example, these results in a larger stretching of the overburden and correspondingly larger time-shifts compared to the Geertsma model. Thus the strain field due to a hard rock layer may explain the high time-shifts observed in deeper layers, as experienced in Shearwater (Staples et al., 2007; Cox et al., 2008). The theory used for the derivation of the method is known for the users of the Geertsma's model, thus the extension proposed in this work can easily be implemented in a code based on Geertsma's analytical solution.
Effectiveness of a New Surfactant-Based Friction Reducer to Extend CT Reach in Openhole Completions—Case Histories from the Middle East
Authors: Noguera Jose Antonio , Sierra Leopoldo
Published: June 2009

Maximizing hydrocarbon recovery by drilling longer horizontal sections or maximizing reservoir contact has presented many challenges to well interventions with coiled tubing (CT). In most cases, the architectural complexity of the wellbore has pushed CT interventions to their limits.

The number of these complex wells has increased significantly in the Middle East in the past few years, especially in new field developments where water-injector wells with the above mentioned characteristics have been placed in the reservoir flanks. These water-injector wells are a perfect example of the completion complexity caused by a combination of large-bore tubular, lower reservoir pressure, and long, horizontal openhole sections.

While preparing a stimulation campaign for water-injector wells on one of the above mentioned fields, because of the complexity of its wellbore architecture, the use of a mechanical assistant tool for CT, such as hydraulic tractors, was considered the only alternative to reach the entire wellbore. However, during the interventions of shorter horizontal sections, it was discovered that a new surfactant-based friction reducer could be used effectively to reduce the drag forces, significantly improving the CT reach. This paper describes cases histories where the use of a new friction reducer allowed the effective stimulation of openhole completions longer than 8,000 ft without using any additional mechanical tools.
CO2 Hydrate: A Possibility for Future CO2 Disposal
Authors: Rajnauth J. , Barrufet M.
Published: June 2009

Capture and disposal of CO2 are actively being sought as a means to avoid release of greenhouse gases to the atmosphere. With the reality of increasing fossil fuel use, focus should be aimed at developing and deploying promising technologies that can prevent release of CO2 to the atmosphere. This must be aggressively pursued with the impetus of increasingly stringent carbon restrictions and problems associated with global warming.

CO2 hydrate offers a possible technology for capturing and disposal of CO2. In this technology CO2 can be captured in the form of hydrate, transported and release at great depths into the ocean. Another option is to form the hydrate in the ocean at condition that allows the hydrate to be thermodynamically stable. This paper will explore the possibility of using CO2 hydrate technology.
Predicting the Onset of Condensate Accumulation Near the Wellbore in a Gas Condensate Reservoir
Authors: Krukrubo G. J. , Gringarten A. C.
Published: June 2009

A gas condensate reservoir usually displays retrograde behavior when the bottomhole pressure falls below the fluid dew point pressure during production. A two-phase mixture of gas and liquid condensate forms and creates regions of different mobilities in the reservoir. These yield a fluid induced composite behavior on well test data.

Reservoir permeability, relative permeability curves, critical condensate saturation and production rate history are some of the factors which determine when the condensate starts to accumulate and when it becomes mobile. The conditions when the condensate bank becomes visible as a composite behavior on the build up derivative response are, however, much less understood. These are addressed in the present paper.

Compositional simulations of simple drawdown-build up sequences were conducted for various drawdown durations, critical condensate saturations, reservoir absolute permeabilities, oil and gas end point relative permeabilities and gas miscibility. Simulated drawdown and build up well test derivative responses were then compared and analyzed.

It was found that, whereas the change in gas mobility is reflected in the drawdown pressure derivative response as soon the pressure falls below the dew point pressure, it is delayed significantly in the build up derivative and only appears when the ratio of the mobility at the start of the build up to that at the end of the drawdown reaches a critical value. This critical value varies little with the parameters investigated in this study (1.7 to 2.1).

The relationship between the time when the mobility change first appear in the build up derivative and the drawdown rate can be represented in all cases investigated by power equations which can then be used to predict when the condensate bank might be seen on the build up derivative for different rates of production and for different reservoir parameters.
Real Options Analysis in Petroleum Exploration and Production: A New Paradigm in Investment Analysis
Authors: Jafarizadeh B. , Bratvold R. B.
Published: June 2009

More than three decades have passed since Stewart Myers coined the term "real options" and introduced this new paradigm into investment science. In the following years a number of publications in both the finance and decision analysis literature hailed the benefits and power of Real Options for corporate investment decisions. In 2001 Copeland stated that "In ten years, real options will replace NPV (Net Present Value) as the central paradigm for investment decisions." Now, eight years hence, the dominating valuation paradigm in the exploration and production industry still seems to be the classical NPV approach. Why?

In the time period following the initial applications of real option valuation to oil & gas investments, a number of approaches were proposed for calculating the value of an uncertain investment. Unfortunately, the assumptions underlying these various approaches and the conditions that are appropriate for their application are often not spelled out. Where they are spelled out or can be inferred, they differ widely from approach to approach and are even contradictory. Furthermore, the difficulties in implementing these approaches are rarely discussed and the pros and cons of alternative approaches are not explained.

Here we will attempt to help remedy this situation by comparing different real option approaches using a relevant oil & gas investment case. The paper concludes with observations about the relative strengths and weaknesses of the proposed approaches, and offers specific recommendations on which ones to use in what circumstances.
Surface Control System Design for Remote Wireless Operations of Intelligent Well Completion System: Case Study
Authors: Ajayi Arashi , Oluwatosin Adedeji , Fasasi Toyin , Giuliani Corrado , Smith Robert , Erumwunse Courage , Cervini Fabio
Published: June 2009

Application of intelligent well technology varies across different locations. In remote areas, the technology has the benefit of providing access to exploiting hydrocarbon assets in hard to reach location. In order to fully utilize the benefit of intelligent well completion for remote control, there must be adequate power and communication infrastructure. These infrastructures are often major constraints in such locations.

This paper describes a case study for the design and implementation of a surface control system and supervisory application of a 3-zone intelligent well completion. The well of interest is located in a remote area of the Niger Delta in Nigeria with limited infrastructure. The design utilizes a wireless system in controlling and optimizing the hydraulically operated downhole interval control valves (ICV) installed in the well.

The surface control system for the 3-zone intelligent well system is an automated, low power surface hydraulic system designed for single well with integrated permanent downhole gauge data acquisition capability. The system is remotely monitored and operated by means of a field management supervisory application located in a controlled environment away from the well location. The system was customized to accommodate power and communication infrastructure constraints available in the field. The system is integrated with a wireless communication system that provides direct control of the installed downhole components. The supervisory application was designed to handle future wells that might be drilled in the field. It serves as a single point of control for all intelligent wells proposed for the field.

The surface hydraulic system and associated components is located on the well platform. The system is protected by a customized external enclosure. The system is powered by a specialized thermoelectric generation unit located in a protective enclosure. The power generation system consists of a battery package that provides current peak / inrush at motor start up and designed to provide 7 days back-up power for the entire system.

The entire system was tested during the system integration test (SIT) to establish system specification before the actual field deployment.

This paper describes the challenges with the design and implementation of low power hydraulic system and methodology for the integration of hydraulically controlled system with wireless technology. The information presented by the authors can be used to design similar systems to develop assets in hard to reach locations.
Effective Stress Coefficient and Biot's Coefficient of Chalk from the Valhall Field, North Sea
Authors: Alam Mohammad Monzurul , Christensen Helle Foged , Fabricius Ida Lykke
Published: June 2009

Deformation of a hydrocarbon reservoir can ideally be predicted by estimating the effective stress acting on it. The effective stress is the difference between the total stress and a fraction (effective stress coefficient) of pore pressure. The effective stress coefficient is thus relevant for studying reservoir deformation and for evaluating 4-D seismic. The effective stress coefficient, α, of chalk from the reservoir zone of the Valhall field, North Sea was estimated from mechanical tests. The coefficient α was compared to Biot's coefficient, β (the dynamic effective stress coefficient) as calculated from density and sonic velocity data. The parameter α is highly relevant for effective stress prediction, as it is directly related to mechanical strain, whereas β is easy to estimate from logging data. Unexpectedly, our data indicate that β measured prior to deformation forms an upper rather than a lower bound for α, so that α cannot be assumed equal to one. During elastic deformation caused by pore pressure drawdown, β predicts α well.
Numerical Modeling of Fully Coupled Hydraulic Fracture Propagation in Naturally Fractured Poro-elastic Reservoir
Authors: Rahman M M , Aghighi Ali , Shaik Abdul Ravoof
Published: June 2009

The effect of a pre-existing natural fracture on the extension of a hydraulically induced fracture has been modeled based on poro-elastic behavior. The approach of Warpiniski and Teufel was adopted to evaluate the fracture propagation that would occur after an induced fracture intersects an existing natural fracture. This two dimensional numerical model will simulate the interaction between an induced propagating fracture and natural fracture.

The model departs radically from current models in that poro-elastic behavior is not used, uniform pressure inside the natural fracture was used in practice this is not true and effect of fracture toughness ignored. A modified leak-off model for intersecting fracture based on poro-elasticity is introduced as the leak-off is increased in the intersection. Besides these previous model used startup solution using PKN model. In this model a triple system of wellbore-fracture-formation is considered and the fracture will initiate first then propagate some extent then interact with natural fracture. A poro-elastic solution for the stresses in the interaction zone has been used as a basis for hydraulic/natural fracture interaction criteria. The criteria compares favorably with the experimental results.

Comparison of the numerical results with experimental results has shown that the main effect of the natural fractures is the width constriction that occurs when the induced fracture propagates into the natural fracture. Numerical and experimental studies for such propagation indicate a near wellbore width and effective length reduction due to the additional normal stress acting on the plane of the induced fracture.
Landuse-based nonpoint source pollution: a threat to water quality in Murchison Bay, Uganda
Authors: Banadda E. N. , Kansiime F. , Kigobe M. , Kizza M. , Nhapi I.
Published: June 2009

Murchison Bay in Lake Victoria is the main water source for Kampala City (Uganda) but is also the recipient for the wastewater discharged from the city. The objective of this paper is to trace the main landuse-based pollution sources within Kampala City borders and around Murchison Bay as a means to develop methods and systems to protect and preserve the aquatic environment and, from the lessons learned, to highlight what is considered to be an appropriate and sustainable approach for Uganda. This paper shows that Uganda needs to set realistic local standards, offer affordable services, set time frameworks, streamline politics, nurture and develop institutions, divide institutional responsibilities, educate her people and learn from the success stories to reverse the negative impacts on the water quality in Murchison Bay.
Living with dams: managing the environmental impacts
Authors: McCartney Matthew
Published: June 2009

Dams, through disruption of physiochemical and biological processes, have water and associated environmental impacts that have far reaching social and economic consequences. The impact of each dam is unique. It depends not only on the dam structure and the attributes of local biota but also climatic and geomorphic conditions. Given the number of existing dams (over 45,000 large dams) and the large number that may be built in the near future, it is clear that humankind must live with the environmental and social consequences for many decades to come. This paper provides a review of the consequences for ecosystems and biodiversity resulting directly from the presence of dams on rivers, and of constraints and opportunities for environmental protection. It illustrates that a wide range of both technical and non-technical measures has been developed to ameliorate the negative impacts of dams. It argues that relatively few studies have been conducted to evaluate the success of these measures and that it is widely perceived that many interventions fail, either for technical reasons or as a consequence of a variety of socio-economic constraints. It discusses the constraints to successful implementation and mechanisms for promoting, funding and ensuring compliance. Finally, it contends that there is a need to improve environmental practices in the operation of both existing and new dams.
Chemical Composition and Sources of PM10 Particulate Matter Collected in San José, Costa Rica
Authors: Herrera Jorge , Rodriguez Susana , Baez Armando P.
Published: June 2009

Measurements of trace metals and inorganic ions were carried out on PM10 aerosols sampled at two sites in the city of San Jose, Costa Rica. Samples were collected with a Thermo Andersen high volume PM sampler on glass fiber and quartz filters. The ions SO42-, NO3-, Cl-, F-, PO43-, NH4+, K+, Na+, Ca2+ and Mg2+ were analyzed by ion chromatography and the trace metals V, Cu, Cr, Pb, Ni, Mn, Fe and Al were analyzed using an atomic absorption spectrometer with a graphite furnace attachment. The results indicated that SO42-was the most abundant ion,
and Al the trace metal with the highest concentration.

Pearson's correlation applied to all data showed a high correlation among SO42-, NO3- and NH4+, indicating a common anthropogenic origin. In addition, the correlation found between Na+ -K+ and Ca2+ -Mg2+ indicated a crustal origin. No correlation was found among the trace metals except Cu-Cr and Fe-Cr. The influence of wind direction on trace metal concentrations is also discussed.
Yields, Quality and Suitability of Four Annual Forages for Deer Pasture in North Central Alberta
Authors: Chapman Grant , Bork Edward , Donkor Noble , Hudson Robert
Published: June 2009

Field pea (Pisum sativum), canola (Brassica napus), turnips (Brassica rapa) and Berseem clover (Trifolium
alexandrinum) were grown in north central Alberta to assess their potential yield and quality and to evaluate their
utilization and preference by white-tailed deer. Herbage DM yield, crude protein (CP), neutral detergent fiber (NDF),
absolute and relative herbage utilization, and dietary preference were the criteria used. The four annual forages produced
over 3, 000 to 11, 000 kg ha-1 DM with canola and turnips producing higher DM yields than field pea and berseem clover.
Forage CP for the four seeded forages ranged from 140 to 305 g kg-1 DM with canola and turnips having higher CP
concentrations than field pea and berseem clover. NDF concentrations ranged from 246 to 480 g kg-1 DM and were lowest
in turnips, intermediate in field pea, and highest in canola and berseem clover. Absolute herbage utilization remained
similar (P>0.05) among the four forage species. In contrast, relative herbage utilization was greater from berseem clover
(66% DM) than field pea (42% DM) or canola (22% DM) or turnips (20% DM). Differences in dietary preference
occurred among the four forages (berseem clover ≥ field pea ≥ turnips ≥ canola). These results suggest that annual
forages, especially berseem clover and field pea, show promise for increasing forage yield and quality and suitability for
late season grazing.
Assessments of the Efficacy of a Long‐Term Application of a Phytoremediation System Using Hybrid Poplar Trees at Former Oil Tank Farm Sites
Authors: El‐Gendy Ahmed S. , Svingos Sotero , Brice Donald , Garretson Joel H. , Schnoor Jerald
Published: June 2009

A poplar tree‐phytoremediation system was installed at former refinery and tank farm sites in Cabin Creek, West Virginia, to clean‐up petroleum‐contaminated‐soils and groundwater. Groundwater and soils in both sites were sampled and analyzed on a regular basis to monitor changes in contaminant concentration since 1999. The concentration of benzene, toluene, ethylbenzene, xylene, and gasoline range organics (GRO) decreased an average of 81%, 90%, 67%, 78%, and 82%, respectively, in the lower soil horizons and 34%, 84%, 12%, 19%, and 59%, respectively, in groundwater. In addition, concentrations of oxygen, methane, and carbon dioxide in soil gas demonstrated that tree roots dewatered soils and allowed penetration of oxygen deep into the soil profile, creating necessary conditions for rhizosphere bioremediation. Although required clean‐up time can limit phytoremediation, it has proven to be a cost‐effective strategy for site improvement if imminent pathways for human exposure and risk are not an issue.
Optimized Reaction Conditions for Removal of Cellular Organic Matter of Microcystis aeruginosa During the Destabilization and Aggregation Process Using Ferric Sulfate in Water Purification
Authors: Pivokonsky Martin , Polasek Pavel , Pivokonska Lenka , Tomaskova Hana
Published: June 2009

The efficiency of removal of cellular organic matter (COM) of cyanobacteria Microcystis aeruginosa from water with ferric sulfate is influenced primarily by coagulant dosage and reaction pH. Therefore, optimization of the reaction conditions is a prerequisite for efficient purification of surface waters. Because the isoelectric point of COM occurs at a low pH, the purification of waters containing this organic matter should take place in an acidic pH range. It was also found that proteins are removed more efficiently than other organic substances (mainly polysaccharides).
Solar Enhanced Wastewater Treatment in Waste Stabilization Ponds
Authors: Agunwamba J. C. , Utsev J. T. , Okonkwo W. I.
Published: June 2009

One of the most popular off‐site wastewater treatment plants used in the tropics is the waste stabilization pond (WSP). Although it has several advantages, its use in urban areas is limited because of its large land area requirement. Hence, this research is aimed at investigating if a solar‐enhanced WSP (SEWSP) can increase treatment efficiency and consequently reduce the land area requirement. The SEWSPs of varying sizes, made of a metallic tank with inlet and outlet valves and a solar reflector, were constructed to increase the incident sunlight intensity. Wastewater samples collected from the inlet and outlet of the SEWSPs were examined for physio‐chemical and biological characteristics for a period of 2 months. The parameters examined were total suspended solids, dissolved oxygen, 5‐day biochemical oxygen demand (BOD 5), chemical oxygen demand (COD), coliform, and Escherichia coli. The efficiencies of the SEWSPs, with respect to these parameters, fluctuated with temperature variation, with the shallowest SEWSP giving the highest treatment efficiency. The research revealed that the cost of treating wastewater using SEWSPs was approximately 2 times lower than the conventional WSP for the same treatment efficiencies.
Development of a Mathematical Model for Physical Disintegration of Flushable Consumer Products in Wastewater Systems
Authors: Karadagli Fatih , McAvoy Drew C. , Rittmann Bruce E.
Published: June 2009

The processes that flushable solid products may undergo after discharge to wastewater systems are (1) physical disintegration of solids resulting from turbulence, (2) direct dissolution of water‐soluble components, (3) hydrolysis of solids to form soluble components, and (4) biodegradation of soluble and insoluble components. We develop a mathematical model for physical disintegration of flushable solid consumer products and test it with two different flushable products—product A, which has 40% water soluble‐content, and product B, which has no water‐soluble components. We present our modeling analysis of experimental results, from which we computed disintegration rate constants and fractional distribution coefficients for the disintegration of larger solids. The rate constants for solids of product A in units of (hour −1) are 0.45 for >8‐mm, 2.25 × 10 −2 for 4‐ to 8‐mm, 0.9 × 10 −2 for 2‐ to 4‐mm, and 1.26 × 10 −2 for 1‐ to 2‐mm solids. The rate constants for solids of product B in units of hour −1 are 1.8 for >8‐mm, 1.8 for 4‐ to 8‐mm, 3.6 × 10 −1 for 2‐ to 4‐mm, and 2.25 × 10 −3 for 1‐ to 2‐mm solids. As indicated by the rate constants, larger solids disintegrate at a faster rate than smaller solids. In addition, product B disintegrated much faster and went mostly to the smallest size range, while product A disintegrated more slowly and was transferred to a range of intermediate solid sizes.
Nitrate and Bisulfide: Monitoring and Patterns in Onondaga Lake, New York, Following Implementation of Nitrification Treatment
Authors: Prestigiacomo A. R. , Effler S. W. , Matthews D. A. , Coletti L. J.
Published: June 2009

Spatial and temporal patterns of nitrate (NO 3 −) and bisulfide (HS −) are documented in mercury‐polluted, culturally eutrophic, Onondaga Lake, New York, following implementation of year‐round nitrification treatment at a domestic wastewater treatment plant (WWTP). Measurements of NO 3 − and HS − in the lake were made with a rapid‐profiling, high‐resolution, in situ ultraviolet spectrophotometer (ISUS) and were validated by standard laboratory wet chemistry analyses. A nearly 2‐fold increase in epilimnetic NO 3 − concentrations, prolonged presence of NO 3 −, and delay of the onset of HS − accumulations in the hypolimnion by approximately 1 month are demonstrated. Detailed vertical patterns resolved within the anoxic hypolimnion first depict operation of the thermodynamically favored NO 3 − reduction process(es) and, subsequently, sulfate (SO 4 2−) reduction and the localization of these processes in the lake's sediments. Variations in the effective depth of entry of WWTP discharge into the lake's water column, ranging from surface waters to metalimnetic depths, are demonstrated. Two‐ and three‐dimensional patterns of NO 3 − from ISUS profiles depict substantial spatial structure mediated primarily by hydrodynamic processes. In situ ultraviolet spectrophotometer measurements of NO 3 − and HS − will play an important role in ongoing rehabilitation programs for the lake.
Synthesis, Characterization, and Application of m‐Phenylendiamine‐Modified Amberlite XAD‐4 Resin for Preconcentration and Determination of Metal Ions in Water Samples
Authors: FeizBakhsh Ali Reza , Panahi Homayon Ahmad , Nezhati Mahshid Nikpour , Amrollahi Maryam , Mahmoudi Faranak
Published: June 2009

A new chelating resin is prepared by coupling Amberlite XAD‐4 (Serva, Heidelberg, New York) with m‐phenylendiamine through an azo spacer, characterized (by elemental analysis, infrared, and thermogravimetric analysis) and studied for preconcentrating nickel(II), cobalt(II), zinc(II), copper(II), and chromium(III) using flame atomic absorption spectrometry for metal monitoring. The optimum pH values for sorption of the above‐mentioned metal ions were 8.5, 8.5, 6.5, 6.5, and 5.5, respectively. The resin was subjected to evaluation through batch binding and column chromatography of the mentioned metal ions. Quantitative desorption occurred instantaneously with 0.5 M HNO 3. Various flowrates of sorption and desorption of nickel(II) have been studied. The sorption capacity was found to be 3.89, 3.27, 2.96, and 3.44 mmol/g of resin for cobalt, copper, zinc, and nickel, respectively. The chelating resin can be reused for 10 cycles of sorption‐desorption without any significant change in sorption capacity. A recovery of >98% was obtained for all the metal ions, with 0.5 M HNO 3 as the eluting agent. The method was applied for determination of metal ions from an industrial wastewater sample.
Microbial Enumeration of Different Functional Groups and Bacterial Behavior in Acid Basic Conditions of a Biotoxic Landfill Leachate of Bahía Blanca, Argentina
Authors: Yunes Fabiana , Baldini Mónica D. , Gómez Marisa A.
Published: June 2009

Leachate is liquid waste from refuse biological decomposition or rainwater percolation in a landfill. This research focused on leachate produced by a landfill in Bahía Blanca, Buenos Aires, Argentina. The research studied the main microbial populations involved in wastewater treatment, analyzed the behavior of bacteria isolated from leachate at different pH values, and appraised leachate biotoxicity. The number of bacteria varied by type, ranging from 1 × 10 4 to 1 × 10 5 CUF/mL aerobic heterotrophic bacteria (AHB); 1 × 10 3 to 1 × 10 5 CUF/mL anaerobic heterotrophic bacteria (ANHB); 1 × 10 5 to 1 × 10 6 CUF/mL sulfite‐reducing bacteria (SRB); 1 × 10 3 to 1 × 10 6 NMP/mL nitrate‐reducing bacteria (NRB); and 1 × 10 2 to 1 × 10 4NMP/mL ammonium‐oxidizing bacteria (AOB).  Several microbial strains developed at pH 5, 7, and 10. These pH values changed to 9 in the culture media after a 48‐hour incubation. Leachate was used to water lettuce seeds (Lactuca sativa capitata). Its toxicity was proved by full inhibition of plant development.
Ozonation in Sequencing Batch Reactors for Reduction of Waste Solids
Authors: Richardson Ege Egemen , Edwards Findlay , Hernandez John
Published: June 2009

The objective of this research was to study a process modification for reducing the mass of waste sludge from sequencing batch reactors (SBRs) by promoting the use of intracellular products released by ozonation of the biomass. For this purpose, biomass generated in laboratory‐scale SBRs was exposed to ozone (O 3) as a cell‐lysing agent to partially solubilize intracellular material. The results indicated that the application of low doses of ozone reduced the mass of waste sludge production by an average of 29%. This positive aspect of the process was achieved using an average daily ozonation rate of 0.0106 mg O 3/mg TSS · h, with slightly less than 2 hours of ozonation per cycle with 3 cycles per day. In addition, the short‐term settling characteristics of the ozonated biomass were observed to have improved. A negative aspect of the ozonation process resulted in decreased effluent quality, as determined by measured increases in the soluble chemical oxygen demand, total Kjeldahl nitrogen, and total phosphorus concentrations of reactor effluent.
Characterization of Landfill Leachates by Molecular Size Distribution, Biodegradability, and Inert Chemical Oxygen Demand
Authors: Amaral Míriam C. S. , Ferreira Cynthia F. A. , Lange Liséte Celina , Aquino Sérgio F.
Published: June 2009

This work presents results from a detailed characterization of landfill leachates of different ages from a landfill in a major Brazilian city. This characterization consists of determining the molecular size distribution and the inert chemical oxygen demand (COD) and the biodegradability of both aerobic and anaerobic processes. Results show that leachate with a high COD concentration leachate has low biodegradability. A significant fraction of the COD is not characterized as protein, carbohydrate, or lipids, which reinforces the hypothesis that the remaining fraction was present in all leachate fractions (less than 1 kDa; between 1 and 10 kDa; between 10 and 100 kDa; and greater than 100 kDa) and is refractory. These results suggest that leachates with such characteristics require treatment systems that use physical‐chemical processes as a pre‐ or post‐treatment step to biological processes.
Chemical Leaching of Metals from Wastewater Sludge: Comparative Study by Use of Three Oxidizing Agents [H 2O 2, FeCl 3, and Fe 2(SO 4) 3]
Authors: Bouda Médard , Hammy Fatima , Mercier Guy , Blais Jean‐François
Published: June 2009

Chemical leaching of the toxic metals (cadmium, chromium, copper, nickel, lead, and zinc) and behavior of other elements (aluminum, calcium, iron, potassium, magnesium, manganese, sodium, phosphorus, and sulfur) in the wastewater sludge of the Montreal Urban Community wastewater treatment plant (Montreal, Quebec, Canada) were studied in 2‐L beakers using sulfuric acid and three oxidants [H 2O 2, FeCl 3, and Fe 2(SO 4) 3] and their association. Metal removal efficiencies of these oxidants were evaluated under different conditions of pH (2.0 and 2.5) and oxidation‐reduction potential (ORP) (350 to 500 mV). The solubilization of the different elements was linked to pH and/or ORP, and a period of 2 to 4 hours was required to obtain satisfactory metals removal yields. Sludge‐fertilizing properties generally were little affected by the decontamination process, especially for processes using a ferric salt. Finally, optimal conditions, for best metals solubilization, were established at pH 2.5 and ORP = 450 mV in a 4‐hour period.
An Exploratory Crossover Study of Learner Perceptions of Use of Audio in Multimedia-Based Tutorials
Authors: Yu Chong Ho , Jannasch-Pennell Angel , Digangi Samuel , Kaprolet Charles
Published: June 2009

While multimedia-based training is prevalent in education, previous studies do not reach consensus on its application. This discrepancy might be due to the fact that multimedia programs implemented in various training programs are very diverse. A multimedia program might include graphics, animation, video, audio, and interactive exercises. This exploratory study is not a bold attempt to answer the question regarding all features of multimedia; rather, the focus has been narrowed down to the audio component of multimedia. It was found that even if audio neither hinders nor helps multimedia learning, a tutorial with audio can hold users' interest and help develop positive perceptions of the presented material, but it is suggested that instructional designers should consider placing rich media content in the later section of the learning sequence, especially when audio can only be used sporadically.