bluuebunny/crossref_metadata_2025 huggingface dataset:
A Review of the Behaviour of Platinum Group Elements within Natural Magmatic Sulfide Ore Systems
Authors: Holwell By D. A. , McDonald I.
Published: January 2010

The largest and most significant type of geological deposit of platinum group elements (PGEs) is that associated with magmatic base metal sulfide minerals in layered mafic or ultramafic igneous intrusions. The common association of PGEs with sulfide minerals is a result of processes of magmatic and sulfide liquid segregation and fractionation. The mineralogical nature of the ores is dependent on a number of factors during sulfide liquid fractionation. The most significant of these with regard to the mineralogy of the two most important metals, platinum and palladium, is the presence and concentration of semimetals such as bismuth and tellurium within the mineralising sulfide liquid. Whereas rhodium, iridium, osmium and ruthenium are almost always present in solid solution within the resultant base metal sulfide minerals; should sufficient semimetals be present, Pd and especially Pt will form discrete minerals (such as platinum bismuthides) around the margins of, and possibly away from, the sulfides.
Primatas da RPPN Gargaú, Paraíba, Brasil
Authors: Fialho Marcos Souza , Gonçalves Gregório Fernandes
Published: January 2010

No abstract
Occasional field observations of the predation on mice, dove and ants by black-tufted-ear marmosets (Callithrix penicillata)
Authors: Silva Ita O. , Alvarenga Adriano B. B. , Boere Vanner
Published: January 2010

No abstract
Towards a hydroinformatics framework to aid decision-making for catchment management
Authors: Hewett C. J. M. , Doyle A. , Quinn P. F.
Published: January 2010

What is the role of hydroinformatics in improving the balance between profitable rural landscapes and environmental quality? Growing recognition of the need for integrated approaches to land and water management, taking account of socio-economic development and environmental considerations, has given rise to concepts such as sustainable development and Integrated River Basin Management. Models and information systems have a place in integrated land–water management, but only if researchers and practitioners engage with wider concerns and work across disciplines. Thus a balanced approach to decision-making is proposed involving partnerships between stakeholders and researchers in the natural and social sciences, using quantitative and qualitative tools. Involvement of stakeholders tied to all scales is essential to building successful partnerships and thus the importance of public engagement is emphasized.

A multi-scale land and water management framework is proposed that attempts to capitalize on current expertise. The place of hydroinformatics tools such as models, GIS and flow visualization software is discussed and a number of specific tools are presented including a novel decision support tool: the Decision Support Matrix. The use of conceptual models to aid communication is discussed and two attempts to apply the framework from projects in the UK and the Western Balkans are presented.
Cost and reliability comparison between branched and looped water supply networks
Authors: Martínez J. B.
Published: January 2010

A new design methodology recently introduced for looped networks is now applied to branched networks. The methodology is based on cost analysis minimisation, network mathematical simulation under normal and failure states and reliability estimates. It is capable of obtaining not only an adequate value for the global reliability of a network but also the appropiate total design demand. This paper then presents a deeper insight into the comparison between looped and branched networks by applying the methodology to both types of networks and comparing the results in terms of cost and reliability. Considerations regarding available reliability definitions are also included which seem to favor volume-type definitions in practice. Results provide a rational foundation to reveal the superiority of looped networks over comparable branched networks by applying quantitative cost evaluations.
Urban water demand forecasting based on HP filter and fuzzy neural network
Authors: Li Wu , Huicheng Zhou
Published: January 2010

Urban water demand is a complex function of socio-economic characteristics, climatic factors and public water policies and strategies. Therefore a combination model is developed based on the multivariate econometric approach which considers these parameters to forecast and manage the urban annual water demand. Firstly, the factors correlative with water demand are selected, then the trend and cyclical components of the factors are calculated by the Hodrick–Prescott (HP) filter method. The multiple linear regression method is applied to simulate the trend components and the fuzzy neural network is built based on the cyclical components, and then the two models are combined to forecast the urban annual water demand. In order to illuminate the model, it is used to forecast the annual water demand of Dalian against actual data records from 1980 to 2007. By comparing with the traditional methods, the preferable model accuracy demonstrates the effectiveness of the fuzzy neural network and multiple linear regression based on the HP filter in forecasting urban annual water demand. After model testing, the sensitivities of the influence factors in the model are analyzed. The results show the model is reliable and feasible, and it also helps to make predictions with less than 10% relative error.
Ant-colony-based simulation–optimization modeling for the design of a forced water pipeline system considering the effects of dynamic pressures
Authors: Abbasi H. , Afshar A. , Jalali M. R.
Published: January 2010

Valve and pump shut-off in water pipeline systems lead to transient flow. This flow is a complex phenomenon and is potentially a very serious problem causing extra dynamic pressure in the system. Within the last few decades, the evolutionary and meta-heuristic algorithms, such as genetic algorithms, simulated annealing. More recently, however, ant-colony optimization algorithms have received considerable attention. In this paper the procedure and application of the ant-colony optimization algorithm to the design of a water supply pipeline system, considering dynamic pressures arising from valve closure, is presented. A simulation–optimization interaction loop (SOIL) is defined that cycles between the steady-state and transient flow modules to describe the hydraulics of the pipeline and ant colony optimization algorithm. A hydraulic simulation module is coupled with the ant colony optimization algorithm to form an efficient and powerful software program which locates the pumping stations at any possible or predefined locations while optimizing their specifications, along with pipe diameters, at each decision point. The model may equally regard or disregard the dynamic pressures.

Two examples are provided to illustrate the proposed methodology which is limited to the solution of any gravity and/or forced water supply pipeline which is typical for water supply systems.
Simulation of urban wastewater systems using artificial neural networks: embedding urban areas in integrated catchment modelling
Authors: Fu Guangtao , Makropoulos Christos , Butler David
Published: January 2010

The urban wastewater system is an important part of integrated water management at the catchment level, yet, more often than not, inclusion of the system and its interaction with the surrounding catchment is either oversimplified or totally ignored in catchment modelling. Reasons of complexity and computational burden are mostly at the heart of this modelling gap. This paper proposes to use artificial neural networks (ANN) as a surrogate for the simulation of the urban wastewater system, allowing for a more realistic representation of the urban component to be incorporated into catchment models within a broad scale modelling framework. As a proof of concept, an integrated urban wastewater model is developed and its response in terms of both quantity and quality in combined sewer overflow (CSO) discharges and treatment plant effluent are captured and used to train a feedforward back-propagation ANN. The comparative results of the integrated urban water model and the ANN show good agreement for both water quantity and quality parameters. The resulting trained network is then embedded into a MIKE BASIN catchment model. It is suggested that ANN models greatly improve the level at which broad scale catchment models can accurately take into account urban–rural interactions.
Parallel computing in conceptual sewer simulations
Authors: Burger G. , Fach S. , Kinzel H. , Rauch W.
Published: January 2010

Integrated urban drainage modelling is used to analyze how existing urban drainage systems respond to particular conditions. Based on these integrated models, researchers and engineers are able to e.g. estimate long-term pollution effects, optimize the behaviour of a system by comparing impacts of different measures on the desired target value or get new insights on systems interactions. Although the use of simplified conceptual models reduces the computational time significantly, searching the enormous vector space that is given by comparing different measures or that the input parameters span, leads to the fact, that computational time is still a limiting factor. Owing to the stagnation of single thread performance in computers and the rising number of cores one needs to adapt algorithms to the parallel nature of the new CPUs to fully utilize the available computing power. In this work a new developed software tool named CD3 for parallel computing in integrated urban drainage systems is introduced. From three investigated parallel strategies two showed promising results and one results in a speedup of up to 4.2 on an eight-way hyperthreaded quad core CPU and shows even for all investigated sewer systems significant run-time reductions.
Treatment of membrane concentrates: phosphate removal and reduction of scaling potential
Authors: Sperlich A. , Warschke D. , Wegmann C. , Ernst M. , Jekel M.
Published: January 2010

The widespread application of nanofiltration (NF) and reverse osmosis (RO) membranes in wastewater reuse inevitably generates a concentrate stream. Due to high concentrations of phosphate and salts, disposal of membrane concentrates is a problem which seriously constrains the application of this technology, especially in inland applications. There is a need for technologies which facilitate an affordable and environmentally-safe disposal of membrane concentrates. The objectives of this study are to investigate appropriate treatment techniques to (1) increase the recovery of the membrane filtration thus minimising the volume of the concentrate stream, and (2) increase the concentrate quality to enable discharge into surface water bodies. The results show that both adsorption onto granular ferric hydroxide (GFH) and chemical precipitation are generally effective for phosphate removal from NF concentrates. Chemical precipitation by dosing of sodium hydroxide solution is rapid and removes more than 90% of phosphate and calcium ions. By the removal of calcium ions, chemical precipitation can significantly reduce the scaling potential of NF and RO concentrates. This may allow higher recoveries in the NF/RO process.
The treatment of run-off from a fertiliser plant for nitrification, denitrification and phosphorus removal by use of constructed wetlands: a demonstration study
Authors: Cooper P. F. , McBarnet W. , O'Donnell D. , McMahon A. , Houston L. , Brian M.
Published: January 2010

The paper describes an evaluation carried out on demonstration scale to show that it was possible to use a Hybrid Reed Bed System comprising a Horizontal flow and a Vertical Flow Bed for treating the high strength run-off from a fertiliser packaging plant. The site is located close to an estuary which is sensitive to nutrients. The environmental regulators were therefore concerned that excessive mass flows of nitrate, ammoniacal nitrogen and phosphate, potentially arising from the site run-off, were not discharged into the estuary. The fertiliser manufacturing company required a simple, low maintenance system for removing nitrogen and phosphorus. A series of experimental runs were carried out to characterise the performance of the Hybrid System, establishing the effluent quality that could be achieved and the mass removal rate which was appropriate for acceptable treatment. These tests showed that it was possible to achieve a reduction of 79% in Total N whilst using molasses as a carbon source for denitrification. When using a 4:1 recycle ratio this produced an effluent with concentrations of 14 mg NH4-N/litre and 18 mg NO3-N/litre from treating site run-off containing concentrations in the order of 75 mg/litre of both NH3N and NO3-N. Chemical dosing with an iron salt brought the P concentration down to around 0.5 mg PO4-P/litre.
The role of the flow pattern in wastewater aeration tanks
Authors: Gresch M. , Braun D. , Gujer W.
Published: January 2010

Reactor hydraulics is one of the key factors for plant performance and plant control. The residence time distribution is a good but limited indicator of reactor hydraulics. A more detailed view is obtained by direct observations within the reactor. Two different techniques (conservative tracer, reactive tracer) are discussed to detect major anomalies in the flow field of a wastewater aeration tank. Experiments with conservative tracers give valuable information over a very limited period of time making the analysis of the flow field difficult. On the other hand, reactive tracers can be monitored long term which helps identifying the flow pattern provided that a high spatial and temporal resolution of the measurements is applied. Experimental data is used to determine the structure and the parameters of a compartment model that corresponds well with the measurements.
Estimation of pollutant loads from urban roadway runoff
Authors: Wada K. , Fujii S.
Published: January 2010

A simulation model consisting of a deposition process and a wash-off process was proposed to evaluate the pollutant loads from urban roadways, and was verified based on field survey data obtained over a 5-year period in the Lake Biwa watershed. The model parameters were determined by minimizing the total sum of squares of differences between the observed data and simulated ones. By applying this model to all roadways in the watershed, the calculated amounts of CODMn, organic carbon, nitrogen and phosphorus in particulate forms were 15.9, 15.7, 0.88 and 0.15 kg/(km2 ·d), respectively, and those in dissolved forms were 14.1, 12.5, 2.62 and 0.03 kg/(km2 ·d), respectively. From the results, the pollutant loads of CODMn, TN and TP obtained for the Lake Biwa watershed (total roadway area of 98.9 km2) were estimated to be 2,950, 350 and 18 kg/d, respectively.
Characterisation of the water quality from open and rope-pump shallow wells in rural Cambodia
Authors: Bennett H. B. , Shantz A. , Shin G. , Sampson M. L. , Meschke J. S.
Published: January 2010

An 8 month investigation into the quality of water from open and rope-pump shallow wells in rural Cambodia was conducted. Wells were analysed for indicators of the health (arsenic, fluoride, manganese, nitrate, total coliforms, E. coli, male-specific coliphage) and aesthetic (iron, chloride, conductivity, total dissolved solids, hardnesss, turbidity, pH) quality of the water, and referenced to the Cambodian Drinking Water Standard when available. The shallow aquifer was chemically less of a health risk than the deep aquifer; however, microbial contamination was considerable for both shallow well types with mean E. coli loads of 103 CFU/100 mL and male-specific coliphage contamination of 102 PFU/eluate. Temporal variation in microbial contamination was significant (p < 0.05), with overall loads decreasing during the dry season. The aesthetic quality of the water was poor for all samples, but worsened during the dry season. No significant difference was observed in the quality of water from open and rope-pump wells, despite their classification as unimproved and improved respectively by the WHO/UNICEF Joint Monitoring Programme. Contaminants present in both well types may readily be removed by simple water treatment, suggesting that household treatment may be more beneficial to rural Cambodian households than shallow aquifer source improvements.
Water quality characterisation of rainwater in tanks at different times and locations
Authors: Kus B. , Kandasamy Jaya , Vigneswaran S. , Shon H. K.
Published: January 2010

Rainwater collected from ten domestic roofs in Sydney and from one in Wollongong, a town south of Sydney, Australia was analysed to determine the water quality and to compare against the Australian Drinking Water Guidelines (ADWG) to determine its suitability as a potable water supply. The pollutants analysed were 13 heavy metals, 8 salts & minerals, pH, ammonia, orthophosphate, conductivity, water hardness, turbidity, total suspended solids, Total dissolved salts & Bicarbonate. The results indicate that the rainwater tested complied to most of the parameters specified in the ADWG. Molecular weight distribution of organic matter from one of the domestic rainwater tanks was analysed in terms of the effects of aging and roof contact. Molecular weight distribution of organic matter in rainwater showed prominent peaks at 37,500 daltons may be due to biopolymers, 850 Da to humic substances, 500 Da to building blocks, 220 Da to low MW acids, and less than 220 Da to amphiphilics. The findings also indicate that the first flush volumes that by-passed the tank can have a significant influence on the water quality in the rainwater tank.
Acute toxicity tests on raw leachate from a Malaysian dumping site
Authors: Sujá Fatihah , Yusof Arij , Osman Md. Anuar
Published: January 2010

Leachate samples collected from the Ampar Tenang open dumping site at Dengkil, Malaysia, were analyzed for acute toxicity. Two in vivo toxicity tests, Acute Oral Toxicity (AOT) and Primary Skin Irritation (PSI), were performed using Sprague Dawley rats and New Zealand Albino rabbits, respectively. The leachate samples were also analyzed chemically for nitrate and phosphate, ammonia-nitrogen, Kjeldahl-nitrogen and Chemical Oxygen Demand (COD). Results from both the AOT and PSI tests showed that the leachate did not contribute to acute toxicity. The AOT test yielded a negative result: no effect was observed in at least half of the rat population. The PSI test on rabbits produced effects only at a leachate concentration of 100%. However, the skin irritation was minor, and the test returned a negative result. The four chemical tests showed high levels of nutrient pollution in the leachate. The nitrate and phosphate concentrations were 2.1 mg/L and 23.6 mg/L, respectively. Further, the ammonia-nitrogen concentration was 1,000 mg NH3-N/L the Kjeldahl-nitrogen level was 446 mg NH3-N/L, and the Chemical Oxygen Demand was 1,300 mg/L. The in vivo toxicity and chemical analyses showed that the leachate is polluted but not acutely toxic to organisms.
Improved removal of arsenic from groundwater using pre-corroded steel and iron tailored granular activated carbon
Authors: Zou J. , Cannon F. S. , Chen W. , Dempsey B. A.
Published: January 2010

The authors have combined corrosion of steel fittings or perforated sheets with granular activated carbon (GAC) that had been pre-treated with Fe(III)-citrate, to produce an innovative and low-maintenance technique for removing arsenic from groundwater. Removal of arsenic was measured using two GAC column configurations: rapid small scale column tests (RSSCT's) and mini-column tests. Independent variables included pH, pre-corrosion procedure, and idling of the column (i.e. intentionally stopping flow for defined times in order to create reducing conditions). Use of corroded steel plus pre-treated GAC removed arsenic to below 10 μg/L for up to 248,000 bed volumes (BV) at pH 6, compared to 7,000 BVs for pre-treated GAC without pre-corroded steel. Performance was not as good at pH 6.5 or 7.5. Idling the system recovered the iron corrosion ability by reducing the passive Fe(III) layer on pre-corroded steel surface, as a result the BVs to arsenic breakthrough was doubled. But idling also caused brief periods of arsenic and iron release after restart, due to reductive dissolution of arsenic-containing ferric oxides. GAC was also effective as filtration media for removal of iron (hydr)oxide particles (and associated arsenic) that was released from the pre-corroded iron.
Aeration characteristics of a rectangular stepped cascade system
Authors: Moulick Sanjib , Tambada Naresh V. , Singh Basant K. , Mal B. C.
Published: January 2010

Aeration experiments, maintaining nappe flow conditions, were carried out on a rectangular stepped cascade of total height 3.0 m to determine the total number of steps, slope of the entire cascade and hydraulic loading rate at which maximum overall aeration efficiency occurs, keeping the surface area of individual steps constant. Based on dimensional analysis, the overall aeration efficiency at standard conditions (E20) was expressed as a function of square of total number of steps (N2) and dimensionless discharge (dc/h), where dc and h represent critical depth in a rectangular prismatic channel and individual step height respectively. An empirical equation with E20 as the response and N2 and dc/h as the independent parameters was developed based on the experimental results subject to 36 ≤ N2 ≤ 196 and 0.009 ≤ dc/h ≤ 0.144. The experimental results showed that the overall aeration efficiency (E20) for a particular step height of stepped cascade increases with increase in dc/h up to a certain value and then decreases. This may be due to at higher dc/h, i.e., at higher hydraulic loading rate, the flow approaches the transition zone and thereby aeration efficiency decreases. E20 was also found to increase with number of steps at any hydraulic loading rate, because of the increased surface area of fall. The optimum number of steps, slope of the entire stepped cascade and hydraulic loading rate were found to be 14, 0.351 and 0.009 m2/s respectively producing the maximum value of overall aeration efficiency of 0.90.
Evaluation on simultaneous removal of particles and off-flavors using population balance for application of powdered activated carbon in dissolved air flotation process
Authors: Kwak D. H. , Yoo S. J. , Lee E. J. , Lee J. W.
Published: January 2010

Most of the water treatment plants applying the DAF process are faced with off-flavors control problems. For simultaneous control of particles of impurities and dissolved organics that cause pungent taste and odor in water, an effective method would be the simple application of powdered activated carbon (PAC) in the DAF process. A series of experiments were carried out to explore the feasibility for simultaneous removal of kaolin particles and organic compounds that produce off-flavors (2-MIB and geosmin). In addition, the flotation efficiency of kaolin and PAC particles adsorbing organics in the DAF process was evaluated by employing the population balance theory. The removal efficiency of 2-MIB and geosmin under the treatment condition with kaolin particles for simultaneous treatment was lower than that of the individual treatment. The decrease in the removal efficiency was probably caused by 2-MIB and geosmin remaining in the PAC particle in the treated water of DAF after bubble flotation. Simulation results obtained by the population balance model indicate, that the initial collision-attachment efficiency of PAC particles was lower than that of kaolin particles
Membranes coupled with physico chemical treatment in water reuse
Authors: Guo W. S. , Zhang R. , Vigneswaran S. , Ngo H. H. , Kandasamy J.
Published: January 2010

In this study, short-term experiments were conducted with different configurations of membrane hybrid systems to treat biological treated sewage effluent containing refractory organic pollutants: (i) submerged hollow fiber microfiltration (SMF) alone; (ii) spiral flocculator (SF)-SMF without settling; (iii) SF-PAC-SMF without settling and (iv) SMF with magnetic ion exchange resin MIEX® pretreatment. The results indicated that the pre-flocculation of SF could improve the mitigation of membrane fouling significantly even when the system was operated at a high membrane filtration rate. The transmembrane pressure (TMP) of SF-PAC-SMF only increased marginally (0.8 kPa over 8 hours). SF-SMF without the addition of powdered activated carbon (PAC) also took a relatively long duration for the TMP to increase. The TMP only increased by 2.5 kPa over 8 hours. The SF-PAC-MF system resulted in a high dissolved organic carbon (DOC) removal of more than 96%. When used as pre-treatment to submerged membranes, the fluidized bed MIEX® contactor could remove a significant amount of organic matter in wastewater. This pre-treatment helped to reduce the membrane fouling and kept the TMP low during the membrane operation.
Reduction of Hexavalent Chromium in Aqueous Medium with Zerovalent Iron
Authors: Dutta Ratnadeepa , Mohammad Sk. Saker , Chakrabarti Sampa , Chaudhuri Basab , Bhattacharjee Sekhar , Dutta Binay K.
Published: January 2010

Hexavalent chromium, emanating primarily from the tannery and electroplating industries, can be reduced to the less toxic trivalent variety by several methods, including reduction with metallic iron. In the present work, electrolytic‐grade iron dust was used to reduce chromium(VI) in the form of potassium dichromate. Loading of iron dust was varied from 0.5 to 1.0 g in 50 mL of solution; the pH of the medium was varied from 1.5 to 3.5; and the initial concentration of the dichromate solution was varied from 50 to 125 mg/L. Under the specified experimental conditions, maximum removal of the hexavalent chromium achieved was approximately 90% of its original value. The time‐concentration data followed a pseudo‐first‐order kinetic model. The conversion and rate of reduction increased with an increase in iron loading and acidity of the medium, whereas an increase in the initial concentration of chromium(VI) caused a decrease in the reduction.
P‐Chlorophenol Wastewater Treatment by Microwave‐Enhanced Catalytic Wet Peroxide Oxidation
Authors: Zhao Guohua , Lv Baoying , Jin Yan , Li Dongming
Published: January 2010

A microwave‐enhanced catalytic wet peroxide oxidation (MW‐CWPO) technology was investigated to treat a high concentration of P‐chlorophenol wastewater under a mild condition. The MW‐CWPO experiments were carried out in a microwave autoclave using copper(II) oxide (CuO)‐loaded active carbon as a catalyst. The P‐chlorophenol was directly ring‐opened within 5 minutes at 343 K and 0.3 MPa and then mineralized to carbon dioxide and water. More than 90% of the total organic carbon was removed within 15 minutes. The reaction activation energy (Ea) of hydrogen peroxide (H2O2) decomposition was decreased from 47.7 to 43.1 kJ/mol under microwave irradiation. The H2O2 catalytic decomposition was fitted to a second‐order reaction under microwave irradiation, while it followed a first‐order reaction without microwave irradiation. The experimental results indicate that the MW‐CWPO method has significant potential applications for a high concentration of P‐chlorophenol wastewater.
Stochastic Calibration of Riverine Water Quality Models
Authors: Parker Geoff T. , Droste Ronald L. , Rennie Colin D.
Published: January 2010

Though commonly used, the suitability of deterministic calibration criteria for stochastic model calibration and uncertainty analysis is unclear. The purpose of this paper is to examine the suitability, relative benefits, and substantial disadvantages of “deterministic‐optimization” approaches, such as root mean square error (RMSE), in stochastic contexts. Three alternate calibration strategies that are suitable for stochastic modeling of water quality under uncertainty are proposed and then demonstrated. The three alternate strategies are the absolute relative error (ARE), weighted relative error, and stochastic exceedance calibration strategy. The findings suggest that potential improvements can be made to current calibration paradigms. The alternate calibration strategies, all of which are based on relative error, were found to match or exceed RMSE calibration strategies, in terms of overall performance, with the enhancement of superior model surface‐response characteristics. Additionally, the application of more stringent ARE criteria offered greater improvement in the stochastic calibration response than increasing the RMSE threshold criteria. Several qualitative benefits of ARE and related metrics also were shown. Because many environmental systems and almost all water quality models are subject to substantial uncertainty, approaches such as those proposed hold substantial, widely applicable benefits.
Phosphorus Removal by Expanded Clay—Six Years of Pilot‐Scale Constructed Wetlands Experience
Authors: Mateus Dina M.R. , Pinho Henrique J.O.
Published: January 2010

Constructed wetlands, which facilitate phosphorus removal via precipitation, adsorption, and biological assimilation, offer a promising appropriate technology for advanced treatment in wastewater treatment plants. Because adsorption and precipitation are pointed out as the major phosphorus‐removal mechanisms, the selection of a medium with high phosphorus‐sorption capacity is important to obtain a sustained phosphorus removal. The objective of this study was to evaluate two kinds of lightweight expanded clay aggregates (LWAs)—Filtralite NR and Filtralite MR (Maxit Group, Avelar, Portugal)—as substrates in constructed wetlands to improve phosphorus‐removal performance. Laboratory experiments were performed to test the potential of the LWAs to remove phosphorus from a phosphate solution. The experimental data were well‐fitted by both the Langmuir and Freundlich isotherm models. Pilot‐scale investigations were carried out to evaluate the phosphorus removal under field conditions. Four subsurface constructed wetlands were operated since June 2002; two of them were planted with Phragmites australis, and the other two were unplanted. The beds were filled with the two kinds of LWAs. Total phosphorous and pH were monitored since 2003, at a mean hydraulic load of 50 ± 4 L/(m2·d), during 6 years. The inflow phosphorus concentration was in the range 4 to 13 mg/L. Under the conditions used, beds with Filtralite MR had better efficiency, and the bed with Filtralite MR planted with Phragmites australis provided a phosphorus effluent mean concentration of 0.7 ± 0.2 mg/L, during the trial period. This study presents the first long‐term pilot‐scale data for constructed wetlands using LWAs.
Homelessness among Older African-American Women: Interpreting a Serious Social Issue through the Arts in Community-Based Participatory Action Research
Authors: Feen-Calligan Holly , Washington Olivia G. M. , Moxley David P.
Published: February 2010

This article describes the incorporation of the arts into a community-based participatory action research (CBPAR) project formulated to develop and test practices for helping homeless older African-American women. Studying how older African-American women become homeless has evolved into developing and testing promising interventions by the Leaving Homelessness Intervention Research Project (LHIRP). The women's participation in creative group activities helped them to communicate their experience with homelessness, express their concerns, develop personal strengths, and obtained mutual understanding. The use of multiple art forms has revealed a number of creative strengths among the participants, which have in turn inspired innovative artistic strategies and methodologies as part of the multiple methods that LHIRP incorporates. These interventions have been useful in helping participants resolve their homelessness. The role and benefit of the arts in CBPAR is described to show how creative activities help researchers and the public to better understand the complexities of homelessness.
Experimental Evaluation of Indirect Heating Tubular Reactors for Solar Methane Pyrolysis
Authors: Rodat Sylvain , Abanades Stéphane , Flamant Gilles
Published: January 2010

Solar thermal pyrolysis of natural gas is studied for the co-production of hydrogen, a promising energy carrier, and Carbon Black, a high-value nano-material, with the bonus of zero CO2 emissions. A 10 kW multi-tubular solar reactor (SR10) based on the indirect heating concept was designed, constructed and tested. It is composed of an insulated cubic cavity receiver (20 cm side) that absorbs concentrated solar irradiation through a quartz window by a 9 cm-diameter aperture. The solar concentrating system is the 1 MW solar furnace of CNRS-PROMES laboratory. An argon-methane mixture flows inside four graphite tubular reaction zones each composed of two concentric tubes that are settled vertically inside the cavity. Experimental runs mainly showed the key influence of the residence time and temperature on the reaction extent. Since SR10 design presented a weak recovery of carbon black in the filter, a single tube configuration was tested with an external plasma heating source. Complete methane conversion and hydrogen yield beyond 80% were achieved at 2073K. Hydrogen and carbon mass balances showed that C2H2 intermediates affect drastically the carbon black production yield: about half of the initial carbon content in the CH4 was found as C2H2 in the outlet gas. Nevertheless, the carbon black recovery in the filtering device was improved with this new configuration. Data are extrapolated to predict the possible hydrogen and carbon production for a future 50 kW solar reactor. The expected production was estimated to be about 2.47 Nm3/h H2 and 386 g/h carbon black for 1.47 Nm3/h of CH4 injected.
Conformation Studies of the Interaction of the Pest-Resistant Toxin from Bacillus thuringiensis with Brown and Red Soils
Authors: Zhou Xueyong , Gao Jianbao , Huang Qiaoyun , Xiong Junfen
Published: January 2010

The secondary structure of the toxin from Bacillus thuringiensis (Bt) is directly correlated with the insecticidal activity and persistence. The conformational changes of Bt toxin before adsorption and after contact with, or adsorbed from, red soil and brown soil were characterized using circular dichroism (CD) and fluorescence spectroscopy. The toxin of Bt contacted with soils for 2 h, the content of ?-helix increased 14.1%-19.0%, and ?-sheet increased 5.1%-5.8%, but the content of the non-regular coil decreased. There was a minor change bout the content of the ?-turns. The fluorescence intensity of contacted toxin decreased and retained 72.8%-93.7% of the intensity of native toxin. The blue-shifts (2.5-3.5 nm) of maximum emission wavelength were observed. The influential trend of desorption was in agreement with the contact course, the influential extent, however, the former was higher than the latter. The content of ?-helix of desorbed toxin increased 33.1%-33.8%, and ?-sheet increased 17.3%-26.8%. The fluorescence intensity retained 70.4%-91.4% and blue-shifts of 3.5 nm were observed.
Approximate Solution of Time-Fractional Chemical Engineering Equations: A Comparative Study
Authors: Khan Najeeb Alam , Ara Asmat , Mahmood Amir
Published: January 2010

In this paper, we present the approximate solutions of the time fractional chemical engineering equations by means of the variational iteration method (VIM) and homotopy perturbation method (HPM). The fractional derivatives are described in the Caputo sense. The solutions of the chemical reactor, reaction, and concentration equations are calculated in the form of convergent series with easily computable components. We compared the HPM against the VIM; an additional comparison will be made against the conventional numerical method. The results show that HPM is more promising, convenient, and efficient than VIM.
A Model for Easily Incorporating Team-Based Learning into Nursing Education
Authors: Mennenga Heidi A. , Smyer Tish
Published: January 2010

A sense of urgency exists among nurse educators to determine the best possible teaching strategies to create a rich, engaging learning environment for students. With the calls for transformation, innovation, and excellence in nursing education from the American Association of Colleges of Nursing, the National Council of State Boards of Nursing, and the National League for Nursing, educators may determine that current teaching strategies fall short. Team-based learning, an innovative teaching strategy, offers educators a structured, student-centered learning environment and may be effective in teaching necessary skills to students. An overview of how this strategy fosters many of the essential concepts, such as critical thinking, professionalism, communication, and interprofessional teamwork, is presented. Additionally, this article offers a clearly delineated "recipe" for implementing team-based learning in the classroom. This innovative strategy has the potential to transform nursing education and provide a positive teaching and learning environment for both educators and students.
SIRT1 mRNA Expression May Be Associated With Energy Expenditure and Insulin Sensitivity
Authors: Rutanen Jarno , Yaluri Nagendra , Modi Shalem , Pihlajamäki Jussi , Vänttinen Markku , Itkonen Paula , Kainulainen Sakari , Yamamoto Hiroyasu , Lagouge Marie , Sinclair David A. , Elliott Peter , Westphal Christoph , Auwerx Johan , Laakso Markku
Published: January 2010

OBJECTIVE

Sirtuin 1 (SIRT1) is implicated in the regulation of mitochondrial function, energy metabolism, and insulin sensitivity in rodents. No studies are available in humans to demonstrate that SIRT1 expression in insulin-sensitive tissues is associated with energy expenditure and insulin sensitivity.

RESEARCH DESIGN AND METHODS

Energy expenditure (EE), insulin sensitivity, and SIRT1 mRNA adipose tissue expression (n = 81) were measured by indirect calorimetry, hyperinsulinemic-euglycemic clamp, and quantitative RT-PCR in 247 nondiabetic offspring of type 2 diabetic patients.

RESULTS

High EE during the clamp (r = 0.375, P = 2.8 × 10−9) and high ΔEE (EE during the clamp − EE in the fasting state) (r = 0.602, P = 2.5 × 10−24) were associated with high insulin sensitivity. Adipose tissue SIRT1 mRNA expression was significantly associated with EE (r = 0.289, P = 0.010) and with insulin sensitivity (r = 0.334, P = 0.002) during hyperinsulinemic-euglycemic clamp. Furthermore, SIRT1 mRNA expression correlated significantly with the expression of several genes regulating mitochondrial function and energy metabolism (e.g., peroxisome proliferator–activated receptor γ coactivator-1β, estrogen-related receptor α, nuclear respiratory factor-1, and mitochondrial transcription factor A), and with several genes of the respiratory chain (e.g., including NADH dehydrogenase [ubiquinone] 1α subcomplex 2, cytochrome c, cytochrome c oxidase subunit IV, and ATP synthase).

CONCLUSIONS

Impaired stimulation of EE by insulin and low SIRT1 expression in insulin-sensitive tissues is likely to reflect impaired regulation of mitochondrial function associated with insulin resistance in humans.
The Natural Protective Mechanism Against Hyperglycemia in Vascular Endothelial Cells
Authors: Riahi Yael , Sin-Malia Yoav , Cohen Guy , Alpert Evgenia , Gruzman Arie , Eckel Juergen , Staels Bart , Guichardant Michel , Sasson Shlomo
Published: January 2010

OBJECTIVE

Vascular endothelial cells (VECs) downregulate their rate of glucose uptake in response to hyperglycemia by decreasing the expression of their typical glucose transporter GLUT-1. Hitherto, we discovered critical roles for the protein calreticulin and the arachidonic acid–metabolizing enzyme 12-lipoxygenase in this autoregulatory process. The hypothesis that 4-hydroxydodeca-(2E,6Z)-dienal (4-HDDE), the peroxidation product of 12-lipoxygenase, mediates this downregulatory mechanism by activating peroxisome proliferator–activated receptor (PPAR) δ was investigated.

RESEARCH DESIGN AND METHODS

Effects of 4-HDDE and PPARδ on the glucose transport system and calreticulin expression in primary bovine aortic endothelial cells were evaluated by pharmacological and molecular interventions.

RESULTS

Using GW501516 (PPARδ agonist) and GSK0660 (PPARδ antagonist), we discovered that high-glucose–induced downregulation of the glucose transport system in VECs is mediated by PPARδ. A PPAR-sensitive luciferase reporter assay in VECs revealed that high glucose markedly increased luciferase activity, while GSK0660 abolished it. High-performance liquid chromatography analysis showed that high-glucose incubation substantially elevated the generation of 4-HDDE in VECs. Treatment of VECs, exposed to normal glucose, with 4-HDDE mimicked high glucose and downregulated the glucose transport system and increased calreticulin expression. Like high glucose, 4-HDDE significantly activated PPARδ in cells overexpressing human PPAR (hPPAR)δ but not hPPARα, -γ1, or -γ2. Moreover, silencing of PPARδ prevented high-glucose–dependent alterations in GLUT-1 and calreticulin expression. Finally, specific binding of PPARδ to a PPAR response element in the promoter region of the calreticulin gene was identified by utilizing a specific chromatin immunoprecipitation assay.

CONCLUSIONS

Collectively, our data show that 4-HDDE plays a central role in the downregulation of glucose uptake in VECs by activating PPARδ.
Effects of Exenatide Plus Rosiglitazone on β-Cell Function and Insulin Sensitivity in Subjects With Type 2 Diabetes on Metformin
Authors: DeFronzo Ralph A. , Triplitt Curtis , Qu Yongming , Lewis Michelle S. , Maggs David , Glass Leonard C.
Published: January 2010

OBJECTIVE

Study the effects of exenatide (EXE) plus rosiglitazone (ROSI) on β-cell function and insulin sensitivity using hyperglycemic and euglycemic insulin clamp techniques in participants with type 2 diabetes on metformin.

RESEARCH DESIGN AND METHODS

In this 20-week, randomized, open-label, multicenter study, participants (mean age, 56 ± 10 years; weight, 93 ± 16 kg; A1C, 7.8 ± 0.7%) continued their metformin regimen and received either EXE 10 μg b.i.d. (n = 45), ROSI 4 mg b.i.d. (n = 45), or EXE 10 μg b.i.d. + ROSI 4 mg b.i.d. (n = 47). Seventy-three participants underwent clamp procedures to quantitate insulin secretion and insulin sensitivity.

RESULTS

A1C declined in all groups (P < 0.05), but decreased most with EXE+ROSI (EXE+ROSI, −1.3 ± 0.1%; ROSI, −1.0 ± 0.1%, EXE, −0.9 ± 0.1%; EXE+ROSI vs. EXE or ROSI, P < 0.05). ROSI resulted in weight gain, while EXE and EXE+ROSI resulted in weight loss (EXE, −2.8 ± 0.5 kg; EXE+ROSI, −1.2 ± 0.5 kg; ROSI, + 1.5 ± 0.5 kg; P < 0.05 between and within all groups). At week 20, 1st and 2nd phase insulin secretion was significantly higher in EXE and EXE+ROSI versus ROSI (both P < 0.05). Insulin sensitivity (M value) was significantly higher in EXE+ROSI versus EXE (P = 0.014).

CONCLUSIONS

Therapy with EXE+ROSI offset the weight gain observed with ROSI and elicited an additive effect on glycemic control with significant improvements in β-cell function and insulin sensitivity.
Increased matrix metalloproteinases 2 and 9 and tissue inhibitor of matrix metalloproteinase 2 expression is associated with progression from vulvar intraepithelial neoplasia to invasive carcinoma
Authors: MÄÄTTÄ MILLA , SANTALA MARKKU , SOINI YLERMI , TURPEENNIEMI‐HUJANEN TAINA , TALVENSAARI‐MATTILA ANNE
Published: January 2010

Objective. The expression of matrix metalloproteinases 2 (MMP‐2) and 9 (MMP‐9) and tissue inhibitors of matrix metalloproteinases 1 (TIMP‐1) and 2 (TIMP‐2) in vulvar intraepithelial neoplasia (VIN I–III) and in vulvar invasive carcinoma were evaluated. Design. A retrospective study. Setting. Oulu University Hospital, Finland. Sample. The study population consisted of 68 patients with vulvar neoplasia (13 VIN I, 5 VIN II, 6 VIN III and 44 squamous cell carcinomas). Methods. Paraffin‐embedded tissue samples were examined by immunohistochemistry. Main outcome measures. MMP‐2, MMP‐9, TIMP‐1 and TIMP‐2 expression in VIN compared to vulvar carcinoma. Results. In VIN I–III MMP‐2 expression was positive in 13%, MMP‐9 in 13%, TIMP‐1 in 50% and TIMP‐2 in 17% of patients. The positive expressions in patients with vulvar carcinoma were 52% for MMP‐2, 36% for MMP‐9, 41% for TIMP‐1 and 78% for TIMP‐2. Conclusions. We conclude that over‐expression of MMP‐2, MMP‐9 and TIMP‐2 may be associated with the progression from VIN to invasive vulvar squamous cell carcinoma.
Incidence of pulmonary embolism and other chest findings in younger patients using multidetector computed tomography
Authors: Herédia Vasco , Ramalho Miguel , Zapparoli Mauricio , Semelka Richard C.
Published: January 2010

Background: Multidetector computed tomography (MDCT) has become the first-line modality for imaging patients with suspected pulmonary embolism (PE). The disadvantages of MDCT, the use of ionizing radiation and iodinated contrast agents, are a reasonable cause of concern, especially in young patients, and therefore it is critical to understand the likelihood of PE in these patients to evaluate a risk benefit analysis.

Purpose: To calculate the incidence of PE and other chest findings on MDCT in a young adult population investigated for PE.

Material and Methods: 387 consecutive patients (age 31.5±13.5 years) underwent chest MDCT for clinically suspected PE between January 2004 and August 2006. Incidence of PE and other chest findings were calculated with a confidence interval of 95% using binomial distribution.

Results: PE incidence was 5%; negative PE with other chest findings was 60%. In 89% of the patients with other chest findings, these included findings of the pleura and/or lung parenchyma. The main patterns of disease were lung opacification suggesting pneumonia (41%), atelectasis (12.4%), and nodular/mass findings (17.5%). In 34% of the patients, there was no PE and no other findings present.

Conclusion: There is a low incidence of PE in young patients imaged for PE with MDCT.
A new glacier inventory on southern Baffin Island, Canada, from ASTER data: I. Applied methods, challenges and solutions
Authors: Svoboda Felix , Paul Frank
Published: February 2010

The quantitative assessment of glacier changes as well as improved modeling of climate-change impacts on glaciers requires digital vector outlines of individual glacier entities. Unfortunately, such a glacier inventory is still lacking in many remote but extensively glacierized gions such as the Canadian Arctic. Multispectral satellite data in combination with digital elevation models (DEMs) a particularly useful for creating detailed glacier inventory data including topographic information for each entity. In this study, we extracted glacier outlines and a DEM using two adjacent Terra ASTER scenes acquired in August 2000 for a remote region on southern Baffin Island, Canada. Additionally, Little Ice Age (LIA) extents we digitized from trimlines and moraines visible on the ASTER scenes, and Landsat MSS and TM scenes from the years 1975 and 1990 we used to assess changes in glacier length and area. Because automated delineation of glaciers is based on a band in the shortwave infrared, we have developed a new semi-automated glacier-mapping approach for the MSS sensor. Wrongly classified debris-coved glaciers, water bodies and attached snowfields we corrected manually for both ASTER and MSS. Glacier drainage divides we manually digitized by combining visual interptation with DEM information. In this first paper, we describe the applied methods for glacier mapping and the glaciological challenges encounted (e.g. data voids, snow cover, ice caps, tributaries), while the second paper ports the data analyses and the derived changes.