bluuebunny/crossref_metadata_2025 huggingface dataset:
A decade of tomography
Authors: Woodward Marta Jo , Nichols Dave , Zdraveva Olga , Whitfield Phil , Johns Tony
Published: October 2008

Over the past 10 years, ray-based postmigration grid tomography has become the standard model-building tool for seismic depth imaging. While the basics of the method have remained unchanged since the late 1990s, the problems it solves have changed dramatically. This evolution has been driven by exploration demands and enabled by computer power. There are three main areas of change. First, standard model resolution has increased from a few thousand meters to a few hundred meters. This order of magnitude improvement may be attributed to both high-quality, complex residual-moveout data picked as densely as [Formula: see text] to [Formula: see text] vertically and horizontally, and to a strategy of working down from long-wavelength to short-wavelength solutions. Second, more and more seismic data sets are being acquired along multiple azimuths, for improved illumination and multiple suppression. High-resolution velocity tomography must solve for all azimuths simultaneously, to prevent short-wavelength velocity heterogeneity from being mistaken for azimuthal anisotropy. Third, there has been a shift from predominantly isotropic to predominantly anisotropic models, both VTI and TTI. With four-component data, anisotropic grid tomography can be used to build models that tie PZ and PS images in depth.
Automatic velocity analysis via shot profile migration
Authors: Shen Peng , Symes William W.
Published: October 2008

We described an implementation of differential semblance velocity analysis based on shot-profile migration, and illustrated its ability to estimate complex, strongly refracting velocity fields. The differential semblance approach to velocity analysis uses waveform data directly: it does not require any sort of traveltime picking. The objective function minimized by the differential semblance algorithm can measure either focusing of the image in offset or flatness of the image in (scattering) angle. We showed that the offset variant of differential semblance yields somewhat more reliable migration velocity estimates than does the scattering angle variant, and we explain why this is so. We observed that inconsistency with the underlying model (Born scattering about a transparent background) can lead to degraded velocity estimates from differential semblance, and we showed how to augment the objective function with stack power to enhance ultimate accuracy. A 2D marine survey over a target obscured by the lensing effects of a gas chimney provides an opportunity for direct comparison of differential semblance with reflection tomography. The differential semblance estimate yields a more data-consistent model (flatter angle gathers) than does reflection tomography in this application, resulting in a more interpretable image below the gas cloud.
Deconstructing Power, Privilege, and Silence in the Classroom
Authors: Ochoa Gilda L. , Pineda Daniela
Published: October 2008

While teaching about race/ethnicity and class from a critical pedagogical standpoint, not only might we encounter student resistance to learning about systems of domination, but we should also be aware of the ways that power, privilege, and exclusion in the larger society may be reproduced in our own classrooms. In this article, we recount how we used free-writes and various discussions in an attempt to deconstruct the power dynamics in an upper division seminar on Latinas/os and education. Though a majority of the students were first generation Latinas, middle and upper middle class white students were more likely to share their perspectives and experiences in the course. This resulted in a situation where class discussions were steered away from the focus of Latinas/os and unequal educational practices to a perspective that reinforced an ideology of equality and a climate that privileged dominant modes of classroom communication. Our experiences suggest that deconstructing classroom dynamics and engaging in collaborative teaching can create more democratic spaces that enhance student learning and challenge hegemonic teaching practices and classroom structures.
Bridging the Divide: Connecting Feminist Histories and Activism in the Classroom
Authors: Blake Holly , Ooten Melissa
Published: October 2008

This article explores the course objectives, pedagogy, and texts/assignments of the course “Gender, Race and Activism.” Learning about the historical traditions of social movements is critical for today's students. They need social justice role models in order to understand what has changed as a result of people's organized and individual efforts over time, and to learn from the successes and challenges of past movements in order to know that change is not only possible but that they, too, can be change agents. When students are exposed to the depth and breadth of activist histories - histories of which they have little to no knowledge - they think more critically about their own education in terms of what stories they have been taught and what/who have been left out. They also become inspired by the successes and challenges of past movements and seek more knowledge, including tools to effectively engage in social activism themselves. Indeed, the underlying premise of the course is to have students make connections between history, theory, and praxis. By instructing students to conduct social justice action projects, the course creates a bridge between historical knowledge and informed activism. The students leave the course more historically informed and better equipped to address present-day challenges. “Gender, Race and Activism” is one requirement of the WILL program at the University of Richmond, which combines coursework in women, gender and sexuality studies with community activism and leadership opportunities for women students.
Open Veins, Public Transcripts: The National Security Archive as a Tool for Critical Pedagogy in the College Classroom
Authors: Hingson Jesse
Published: October 2008

Since 2004, I have used various document sets from the National Security Archive (NSA) to teach students about modern Latin American history at Georgia College and State University, a medium-sized public liberal arts university in central Georgia. The NSA has the largest non-governmental online collection of US national security government documents in the world. Its research staff compiles, introduces, contextualizes, analyzes, and sifts through thousands of declassified materials. These include inter-agency memos, embassy communications, executive directives, confidential correspondence, and other once-classified materials.

This essay will critically examine the NSA as a way of teaching the histories of US imperialism and intervention, state suppression of popular dissent, militarism, human rights abuses, and counterinsurgency tactics and training in Latin America from the beginning of the Cold War until today. First, I will provide an explanation of the assignments that I use. These consist mostly of document analysis exercises and larger research papers. I will also share which topics students tend to explore, while noting several potential methodological pitfalls in using the NSA documents. Secondly, I will share testimony on how students' views on US foreign policy have changed. The general consensus at the beginning of the semester is that one of the principal aims of US foreign policy is to promote democracy above all other values. After examining the NSA documents, however, students seriously re-examine this idea. Indeed, introducing students to the `raw material' provided by the NSA is a powerful pedagogical tool for delivering and teaching radical history.
Theater of the Assessed: Drama-Based Pedagogies in the History Classroom
Authors: Mattson Rachel
Published: October 2008

This essay argues that the current crisis in history education at the K-12 levels requires creative interventions and interdisciplinary collaborations. It also offers a series of strategies for teaching critical historical thinking skills to young people. Drawing on the author's recent collaboration with a theater educator, the essay examines the radical potential of one pedagogical method in particular—a theater-based strategy called “process drama.” A philosophical and experiential approach to teaching and learning, this method draws on theatrical ideas to trouble the traditional dynamics of the classroom and provoke students into critical investigation. The author roots her reflections on the power and potential of process drama for history education in a lesson she developed for a group of public school teachers from the Bronx. Interested in introducing these teachers to a diversity of visual primary source documents and in complicating the story of the Civil Rights movement, she asked participants to use a series of theater exercises to examine a set of photographs taken at civil rights protests. This work, the author argues, suggests the power of critical and creative pedagogies in the history classroom; demonstrates the importance of interdisciplinary instruction, even at the K-12 levels; and offers a model for social justice history education that does not ignore the practical demands that weigh heavy on classroom teachers in this current standards-saturated public school educational climate.
Transformations through Teatro: Culture Clash in a Chicana/o History Classroom
Authors: García David G.
Published: October 2008

This article describes the creation and implementation of a unique undergraduate history seminar dedicated to examining and engaging the work of the Chicano-Latino theater trio Culture Clash. My previous research identified similarities between Culture Clash's playwriting methods and scholarly approaches to oral history and ethnography. The course engaged these methods, requiring students to conduct oral histories and transform those interviews into performance monologues. Informed by the role of Chicana/o teatro in the social protest movements of the 1960s and 1970s, the course challenged students to follow Culture Clash's methods of using teatro to tell the stories of those on society's margins. Culture Clash members joined the class in facilitating students' efforts to bridge historical scholarship with oral histories of everyday people. I examined excerpts of students' monologues and a spoken word piece performed as part of the course culminating public “Reader's Theater” event. Reflecting on some of the students' remarks, I discuss the seminar as contributing to a tradition of transformative history pedagogy.
The Standardized Curriculum and Delocalization: Obstacles to Critical Pedagogy
Authors: Mulcahy Donal E. , Irwin Judith
Published: October 2008

This essay explores the nature of standardized curricula and the ideological motivation behind the standards movement, beginning with President Ronald Reagan in the early 1980s. It focuses on how the standardizing of curricula and the embedded hierarchy of information and knowledge—produced by few and mandated for all—not only reflects a privileged epistemology but does so with the intention of maintaining a social structure that will continue to serve the elite. We address the deskilling of teachers in the K-12 classroom through centralized, mandated curricula as a means of encouraging teachers' complicity in promoting an anti-intellectual, hegemonizing school structure. In particular we examine how the New York City public school teacher is stifled by such an approach to education. In addition to a critique of the standards movement and the bureaucratized, hierarchical approach to schooling, this essay offers an alternative approach. The alternative we suggest focuses attention on the classroom over the district office. It also privileges the wants and needs of the community over those of the corporate economy and its influence on education policy. The teacher in the classroom should have the authority to engage students in a living curriculum that pertains to their daily lives. The community must determine what this curriculum is rather than federal government officials who lack local knowledge.
Specific Chemiluminescence from Singlet Oxygen Generated by the Reaction of Acetonitrile and Hydrogen Peroxide in the Presence of Alkali Halide
Authors: Suzuki Kosuke , Saito Hirotaka , Jinno Naoya , Hashimoto Masahiko , Tsukagoshi Kazuhiko , Kimoto Hideshi
Published: October 2008

We developed a detection apparatus, equipped with two photomultiplier tubes, for chemiluminescence from singlet oxygen: the dimol light emission (ca. 634 nm) and the monomol light emission (ca. 1270 nm). Singlet oxygen was generated by reactions between sodium hypochlorite and hydrogen peroxide and between acetonitrile and hydrogen peroxide, and the dimol and monomol chemiluminescence emission were simultaneously observed using the apparatus. It was found that the chemiluminescence of the monomol emission in the acetonitrile system was enhanced in the presence of alkali halides and lasted more than 1.5 h, while the dimol emission in the acetonitrile system and the dimol and monomol emission in the hypochlorite system were not affected by the presence of alkali halide. The effects of antioxidants and nucleosides on monomol chemiluminescence in the acetonitrile system were examined. The specific chemiluminescence of the monomol emission of singlet oxygen in the acetonitrile system in the presence of alkali halides and the initial data concerning antioxidants and nucleosides will be useful in the design of new analytical systems or in elucidating the mechanism of chemiluminescence emission from singlet oxygen.
Michael Addition Reaction of Alkenyl Trichloroacetates Catalyzed by Dibutyltin Dimethoxide
Authors: Yanagisawa Akira , Izumi Youhei , Arai Takayoshi
Published: October 2008

The Michael addition of alkenyl trichloroacetates to p-benzoquinone was achieved using dibutyltin dimethoxide as a catalyst in a mixed solvent consisting of THF and MeOH. Various monoalkylated benzoquinone derivatives were obtained from cyclic and acyclic trichloroacetates in moderate yield. trans-β-Nitrostyrene was also a favorable electrophile in this catalytic process, which gave an expected Michael adduct.
Photochemical Metallization of DNA
Authors: Zinchenko Anatoly A , Chen Ning , Murata Shizuaki
Published: October 2008

Upon UV irradiation of silver(I) ion solutions containing alcohol as reduction agents, metal nanoparticles are grown on a DNA polymer chain. This metallization is independent of the DNA double-helicity and is controlled by the chemical structure of alcohol as well as by the wavelength of the light source.
Lewis Acid-catalyzed Asymmetric Fluorinations of β-Keto Esters: Dramatic Improvement in Enantioselectivity by Changing the Operation Sequence
Authors: Shibatomi Kazutaka , Tsuzuki Yuya , Iwasa Seiji
Published: October 2008

Efficient Lewis acid-catalyzed asymmetric fluorination and chlorination of β-keto esters were achieved using hybrid chiral oxazoline ligand 1. The enantioselectivity of the halogenated products dramatically increased when the reaction procedure was changed.
Formation of Inclusion Complexes of Isotactic and Syndiotactic Poly(methyl methacrylate)s with γ-Cyclodextrin
Authors: Kida Toshiyuki , Kikuzawa Akira , Akashi Mitsuru
Published: October 2008

We report here inclusion complex formation between γ-cyclodextrin (γ-CD) and stereoregular poly(methyl methacrylate)s (PMMAs). γ-CD was found to form an inclusion complex with isotactic (it) PMMA more effectively than with syndiotactic (st) PMMA. The formation of an inclusion complex between γ-CD and st-PMMA was strongly influenced by the amount of γ-CD added, and the addition of an excess amount of γ-CD was required for γ-CD–st-PMMA complex formation.
Superhydrophilicity of Rutile TiO2 Prepared by Anodic Oxidation in High Concentration Sulfuric Acid Electrolyte
Authors: Masahashi Naoya , Mizukoshi Yoshiteru , Semboshi Satoshi , Ohtsu Naofumi
Published: October 2008

The contact angles of rutile TiO2 prepared by anodic oxidation in an electrolyte with a high concentration of sulfuric acid is almost zero without UV illumination. The water droplet spread across the surface within 1 ms because of the strong interaction with the hydroxy groups.
The disclosure of medical errors: a catalyst for litigation or the way forward for better patient management?
Authors: Wright James , Opperman Guy
Published: October 2008

There is enshrined, within the General Medical Council's Good Medical Practice Guidelines, a professional duty imposed upon doctors to advise patients when medical errors have occurred. This issue has recently been exalted by calls from the National Health Service Litigation Authority for hospitals and doctors to adopt a more open and honest culture about disclosing medical errors to patients who have been injured during treatment. This request, and indeed obligation, to disclose medical errors does not seem to be manifesting with great regularity in clinical practice. This is despite the ethical and practical reasons for such disclosure, and its potential to reduce litigation against doctors and hospitals and by association the significant sums paid out each year in damages and legal costs, which money could more readily be directed towards improving patient care.
Experiences of Medical Advisors in the Workers' Compensation System in British Columbia
Authors: Arnold-Smith Lydia , Harder Henry G.
Published: October 2008

Attending physicians and medical advisors, physicians contracting their services to the Workers' Compensation Board, have key roles in assisting injured workers to return to work. A literature review of the role of the physician in the compensable return to work process reveals a lack of information regarding the experiences of medical advisors. This descriptive phenomenological study was undertaken to explore the lived experiences of four medical advisors in a northern rural service delivery location. The purpose of the research was to gain an understanding of the medical advisors' experiences in the compensable return to work process and in the compensation system. Analysis of the interview data revealed a central theme of commitment to quality medical care for injured workers, along with three major themes and several minor themes subsumed within the major concepts: providing medical opinions — requiring factual information, clarifying the diagnosis, no previous relationship with worker, categories of injuries; working with attending physicians and specialists — building relationships, evidence based treatment plans, role of the attending physician, role of the medical advisor; and, working within the workers' compensation environment — structure and policies, expedited services, and case management/team environment. This research report presents the central theme as the foundation through which the major themes are interconnected. This study does not generalise to all medical advisors, but relays stories that contain the essence of a lived experience.
Design Aspects of Self-Organizing Heterogeneous Multi-Core Architectures Entwurfsaspekte selbstorganisierender, heterogener Multicore-Architekturen
Authors: Buchty Rainer , Karl Wolfgang
Published: October 2008

Already today we face architectures featuring up to several hundreds of processors, being able to manage several thousand concurrent threads. Future architectures, however, will not only see an increase in parallelism but also feature an increase in heterogeneity and reconfigurability. Judging from current production and prototype architectures, we also see that such systems will be tiled, i. e., individual cores with local memory interconnected through some means of on-chip communication. Current discussions show that existing approaches to application mapping, parallelization, data locality optimization, and system management do not match these upcoming architectures well, thus rather hampering than harnessing the power of future systems. We will therefore outline the requirements of upcoming architectures and demonstrate how self-organization, including bio-inspired, techniques may help to manage system complexity. Key to these techniques is a sophisticated decentralized, hierarchical monitoring approach suitable for sustained real-time monitoring and event correlation for current and future high-performance architectures.
Survival Comparison of Spring Chinook Salmon Reared in a Production Hatchery under Optimum Conventional and Seminatural Conditions
Authors: Fast David E. , Neeley Douglas , Lind David T. , Johnston Mark V. , Strom Charles R. , Bosch William J. , Knudsen Curtis M. , Schroder Steve L. , Watson Bruce D.
Published: October 2008

We found insufficient evidence to conclude that seminatural treatment (SNT; i.e., rearing in camouflage‐painted raceways with surface and underwater structures and underwater feeders) of juvenile Chinook salmon Oncorhynchus tshawytscha resulted in higher survival indices than did optimum conventional treatment (OCT; i.e., rearing in concrete raceways with surface feeding) for the specific treatments and environmental conditions tested. We reared spring Chinook salmon from fry to smolt in paired raceways under the SNT and OCT rearing treatments for five consecutive years. For four to nine SNT and OCT raceway pairs annually, we used passive integrated transponder, coded wire, and visual implant elastomer tags to compare survival indices for juvenile fish from release at three different acclimation sites 340‐400 km downstream to passage at McNary Dam on the Columbia River, and for adults from release to adult return to Roza Dam in the upper Yakima basin. The observed differences in juvenile and adult survival between the SNT and OCT fish were either statistically insignificant, conflicting in their statistical significance, or explained by significant differences in the presence of the causative agents of bacterial kidney disease in juvenile fish at release.
An adequate theory for the shear strength of reinforced concrete structures
Authors: Collins M. P. , Bentz E. C. , Sherwood E. G. , Xie L.
Published: October 2008

Traditional shear design procedures for concrete structures rely on empirical equations derived from laboratory experiments and lack the type of adequate theory that forms the basis of flexural design. As shear resistance depends on so many variables and because laboratory tests do not cover the full practical range of parameters, empirical shear design equations can result in structures with inadequate shear strength. Recent failures of such structures have highlighted the need for shear design provisions solidly based on an adequate theory. This paper introduces such a theory and explains the simple design models derived from the theory, which include a strut-and-tie model for disturbed regions and a sectional model for flexural regions. These models form the basis of the shear provisions on the 2004 Canadian standard for the design of concrete structures. In the current paper, results from nine major experimental series are compared with predictions from the new shear provisions and with predictions from the shear provisions of the Eurocode and the American Concrete Institute code. It is demonstrated that the new shear design provisions are capable of predicting the shear strength of reinforced concrete members and prestressed concrete members with considerably greater reliability.
Drinking water treatment plant assessment through performance indicators
Authors: Vieira P. , Alegre H. , Rosa M. J. , Lucas H.
Published: October 2008

Performance assessment (PA) of urban infrastructure services, mainly in the case of water systems, is becoming a major issue worldwide. Therefore, in the last decade, the need for a clear definition of management objectives of water services and the subsequent need to monitor goals achievement have led to the development of some initiatives to tackle the evaluation of the efficiency of those services, their main aim being the definition of systems of performance indicators. However, these PA systems are strongly oriented by a management/economic perspective and technical aspects have often been ignored. In addition, none of them has specifically addressed the drinking water treatment.

This paper presents a proposal for a PI system that applies to drinking water treatment facilities as a part of a standardised methodology for performance assessment. In total, ca. 80 PI have been defined and classified according to seven evaluation domains, namely: treated water quality; plant reliability; use of natural resources and raw materials; by-products management; safety; human resources; and, economical and financial resources.
Where do the odorous halogenated phenols in drinking water resources come from?
Authors: Bruchet A. , Prolongeau C. , Esperanza M. , Coquery M.
Published: October 2008

An SPME-GC/MS method was optimised for the analysis of halogenated phenols in raw and treated wastewaters. Method detection limits range from 50 to 200 ng/L in treated wastewaters. The method was applied at six wastewater plants sampled on three consecutive days. Seven halophenols were found in the wastewater effluents at concentrations up to 340 ng/L. It is concluded that wastewater emissions contribute to the presence of halophenols in water resources and, depending on the dilution ratio, may represent an organoleptic threat during the subsequent production of drinking water.
Evaluation of source water quality for selection of drinking water purification system
Authors: Hayashi N. , Yokota H. , Furumai H. , Fujiwara M.
Published: October 2008

When renewing water purification facilities, it is important to select a suitable purification system that can accommodate the quality of the respective source water. The Japan Water Research Center has been collecting a large amount of water quality data from drinking-water utilities across Japan, categorising and analysing these data, and evaluating the suitability of water purification processes. Multivariate analyses such as hierarchical cluster analysis and principal component analysis were performed to investigate the relationships between the quality of source water used for water supply and various factors that affect the purification process. Based on these results, water sources throughout Japan were clearly categorised into four groups, and suitable water purification systems were identified for the different water quality groups. The results can serve as an important reference for water utilities during future facility renewal projects.
Improving water access indicators in developing countries: a proposal using water point mapping methodology
Authors: Jiménez A. , Pérez-Foguet A.
Published: October 2008

The Millennium Development Goals set the target to “halve by 2015 the proportion of people without sustainable access to safe drinking water and basic sanitation”. The current international definition of indicators of access is insufficient for measuring this target. Furthermore, the lack of an internationally agreed definition and measurement methodology is causing confusion and uncertainty regarding the figures that are disseminated worldwide. Moreover, the current context, in which almost 70% of funds for the sector are channelled through national governments, emphasises the importance of a monitoring system for national water sectors in developing countries. From this, an improvement in investment efficiency is expected. The water point mapping methodology, promoted and widely developed by the international organization WaterAid, is presented as an alternative way of defining water access indicators. The present paper describes its potential for defining new indicators and making improvements. Our research is based on the results of a pilot study carried out by Ingeniería Sin Fronteras (Engineering without Borders, Spain) in the Same district, Tanzania. The paper concludes with a discussion of the challenges posed by the implementation of this methodology and proposes further steps for improvement.
Modeling disinfection by-products: coupling hydraulicand chemical models
Authors: Ghebremichael K. , Gebremeskel A. , Trifunovic N. , Amy G.
Published: October 2008

There are established chemical models that can predict disinfectant decay and DBPs formation with respect to various water quality parameters and reaction time (water age). While models such as EPANET are powerful tools in hydraulic simulations, they have limited use in simulating water quality, containing only a basic chlorine decay subroutine. This paper presents a study on the use of a link that was developed to couple the external water quality models and the hydraulic model of EPANET 2.The coupled model has been applied to a hypothetical distribution system under steady and non steady conditions. Simulations have taken the form of sensitivity analyses to probe operational strategies such as modified treatment as well as optimized secondary disinfection in order to maintain sufficient chlorine residual at critical points within the distribution system. Simulations have also been performed to compare the relative rates of formation of THMs vs HAAs as well as individual species. Of particular interest is optimization of chlorine dose to minimize residual chlorine under non-steady-state conditions.
Modelling the impacts of climate change on a water treatment plant in South Australia
Authors: Thorne O. M. , Fenner R. A.
Published: October 2008

The simplified climate change impact assessment tool (SCIAT) has been developed to address the specific needs of the water industry and provides a tool to translate climate change projections into ‘real world’ impacts. Its application is demonstrated in this study to assess the impacts of climate change on the reservoir water quality and water treatment plant (WTP) operations at Myponga, South Australia. The primary aim is to provide water treatment plant operators with knowledge of the potential impacts and associated probabilities of occurrence of climate change, enabling them to make informed, risk-based adaptation and planning decisions. It was found that climate change alone poses little risk to WTP operations, with the WTP able to operate as normal under all future climate scenarios. This finding not only reflects the specific catchment characteristics of Myponga, but also the assumptions made in this study. When interpreting these findings to develop comprehensive adaptation plans, operators must also take into account potential non-climate changes such as land use and demand.
The impact of climate change on drinking water supply by riverbank filtration
Authors: Eckert P. , Lamberts R. , Wagner C.
Published: October 2008

Riverbank filtration (RBF) is a well proven natural treatment, which in many countries is part of a multi-barrier concept in drinking water supply. The induced infiltration of river water into the aquifer produces a significant improvement in river water quality. Riverbank filtration wells are characterized by a high capacity.

Based on data from recent years, an integrated approach to assessing the impact of climate change on safe drinking water production by RBF is demonstrated in the Lower Rhine Valley, Germany. Influencing factors on quantitative as well as qualitative aspects were identified. During low river water periods, the capacity of the RBF-wells decreases. In addition the lower discharge within the river is accompanied by a increased concentration of several chemical compounds. Together with higher water temperatures which influence the hydrogeochemical processes during RBF, the changing raw water composition has to be considered for the subsequent technical treatment step.

However, our investigations reveal that despite the impact of climate change on RBF, the multi-protective barrier concept, including both natural and technical purification, has proven a reliable method for drinking water production. The sanitation of the Rhine over the last decades was an important step to make RBF more resilient to climate change.
Influencing attitudes and changing consumers' household water consumption behaviour
Authors: Cary J. W.
Published: October 2008

Programs for demand management have become critical following extended water shortage in Australia. Changing attitudes is a major element of water conservation programs. Information and education are likely to be necessary but not sufficient components of any program for behaviour change. A combination of factors is needed to promote water saving behaviour. Changing the behaviours of less responsive water users requires a better understanding of what shapes water conservation behaviours. Programs and conservation behaviour models need to take account of both ‘internal’ influences, such as attitudes and habits, and ‘external’ influences, such as the water delivery environment, pricing and social norms for water use.
Assessment and management of risk associated with bromate formation in drinking water
Authors: Quang Z. Do , Baudin I. , Bonnard R. , Deveughèle S.
Published: October 2008

The objective of this work is the development of a global methodology for the evaluation and management of the risk of bromate formation associated with the ozonation of drinking water in order to anticipate the upcoming regulation in 2008 regarding the bromate content in water of 10 μg/l. An aid decision tool was developed for the calculation of the risk of bromate formation using water quality data and plant operational conditions which helped to develop operational recommendation guide for ozonation process on the basis of different treatment scenario simulations. The model was adapted, tested and validated on six full scale plants located near Paris area, and can be easily used by the operators in their everyday work. The tool has shown to be efficient in prediction of the bromate risk in treated water for different water qualities and operating conditions and allowed to establish the levels of risk (low, medium and high). It can be used successfully as support to establish guidelines for risk management focusing on optimization of disinfection and oxidation processes involving ozone.
Inactivation of Chironomid larvae with ozone
Authors: Sun Xing-Bin , Cui Fu-Yi
Published: October 2008

In this paper, comparative experiments on the inactivation of Chironomid larvae by ozone and chlorine were conducted. In addition, batch experiments were performed in order to analyze the influence of pH value, organic precursor concentration and temperature on the inactivation efficiency of Chironomid larvae with ozone. Based on it, removal effect of different pre-oxidation combined with coagulation process on Chironomid larvae in raw water was evaluated. The results showed that ozone possessed better inactivation performance than chlorine, and complete inactivation of Chironomid larvae in raw water was obtained at ozone dose of 2.0 mg/L after 25 minutes of contact time. The inactivation rate of Chironomid larvae at pH 6.0 was higher than those found at pH 8.0 in same contact time. Meanwhile, the organic precursor had negative effects on inactivation, indicated by the decreasing inactivation rate from 100% at TOC concentration of 0 mg/L to 20.0% at 8 mg/L after 30 min of contact time. With regard to the temperature, the inactivation efficiency of Chironomid larvae improved with the temperature increasing within the range investigated of 10–25°C. The inactivation rate was reduced by 73.3% when temperature reduced from 25°C to10°C. The coagulation jar test showed that Chironomid larvae in the raw water could be completely removed by ozone pre-oxidation combined with the coagulation process at ozone dosage of 1.2 mg/L.
Sustainability assessment of advanced wastewater treatment technologies
Authors: Høibye L. , Clauson-Kaas J. , Wenzel H. , Larsen H. F. , Jacobsen B. N. , Dalgaard O.
Published: October 2008

As a consequence of the EU Water Framework Directive more focus is now on discharges of hazardous substances from wastewater treatment plants and sewers. Thus, many municipalities in Denmark may have to adopt to future advanced treatment technologies. This paper describes a holistic assessment, which includes technical, economical and environmental aspects. The technical and economical assessment is performed on 5 advanced treatment technologies: sand filtration, ozone treatment, UV exclusively for disinfection of pathogenic microorganisms, membrane bioreactor (MBR) and UV in combination with advanced oxidation. The technical assessment is based on 12 hazardous substances comprising heavy metals, organic pollutants, endocrine disruptors as well as pathogenic microorganisms. The environmental assessment is performed by life cycle assessment (LCA) comprising 9 of the specific hazardous substances and three advanced treatment methods; sand filtration, ozone treatment and MBR. The technical and economic assessment showed that UV solely for disinfection purposes or ozone treatment is the most advantageous advanced treatment methods if the demands are restricted to pathogenic microorganisms. In terms of sustainability, sand filtration is the most advantageous method based on the technical and environmental assessment due to the low energy consumption and high efficiency with regards to removal of heavy metals.
Biosorption of Pb2 +  and Cd2 +  in a Fixed Bed Column with Immobilised Chorella sp. Biomass
Authors: Almaguer Cantu Veronica , Garza-González Ma Teresa , de la Rosa Javier Rivera , Loredo-Medrano Jose Angel
Published: October 2008

The biosorption of Pb2 +  and Cd2 +  in a fixed bed column by immobilised Chlorella sp. was characterised in a fixed bed column. Effect of initial concentration of Pb2 +  and Cd2 + , pH, and pellet size on the biosorption capacity was studied, at laboratory scale, using a factorial experiment design 23, in a 10 cm height × 1 cm of diameter continuous flow column packed with immobilised biomass.

Equilibrium uptake of Pb2 +  and Cd2 + , increased with increasing initial metal ion concentration. It was favoured to pH 5, with a pellet of 5 mm of diameter. Langmuir model described the biosorption equilibrium of both metals.

The biosorption of each single cation was studied too in a large column (50 cm height × 5 cm of diameter) at bench scale with a range of flow of 40 to 80 mL min−1. The mass transfer coefficient was determined fitting the experimental data to continuity equations that were discretised in the radial terms with orthogonal collocation method.
Evaluation of methods for isolation of DNA for polymerase chain reaction (PCR)-based identification of pathogenic bacteria from pure cultures and water samples
Authors: Horáková K. , Mlejnková H. , Mlejnek P.
Published: October 2008

Polymerase chain reaction (PCR) provides a reliable detection of pathogenic bacteria in water samples. However, this method can be adversely influenced by the purity of the DNA template. This is a particularly important obstacle when the bacterial DNA is directly extracted from water samples. In this study we compared the suitability of 8 different methods for isolation of bacterial DNA from pure cultures and 10 different methods for isolation of DNA from water samples. The quality of extracted DNA was assessed by PCR amplification of target sequences derived from uid (E. coli and Shigella sp.), tuf (Enterococcus sp.) and hns (Salmonella sp.). Results indicated that there are differences among the methods tested and only a few of them gave satisfactory results. The method based on alkaline lysis of bacterial suspension, which was developed in our laboratory, seemed to be efficient enough for the detection of bacteria from pure cultures. Detection of bacteria directly from water samples was more difficult. The modified method developed by Slusarenko was found as the best of the tested methods.
Life-cycle energy and CO2 analysis of stormwater treatment devices
Authors: Andrew R. M. , Vesely É.-T.
Published: October 2008

Environmental impacts associated with the construction, maintenance, and disposal of low-impact stormwater management devices are one aspect that should be considered during decision-making and life-cycle assessment (LCA) is a suitable method for quantifying such impacts. This paper reports a pilot study that employs LCA to compare life-cycle energy requirements and CO2 emissions of two stormwater devices in New Zealand. The two devices are a raingarden servicing an urban feeder road, and a sand filter that could have been installed in its stead. With an assumed life-time of 50 years, the life-cycle energy requirements of the built raingarden were almost 20% less than for the sand filter, while the CO2 emissions were 30% less. Our analysis shows that given the difference between the infiltration rates used in the raingarden design (0.3 m/day) and measured during monitoring (3 m/day) there was potential to make significantly greater life-time savings using a smaller design for the raingarden that would have also met the treatment efficiency expectations. The analysis highlights the significant contribution of transportation–of both materials and staff–and ongoing maintenance to a treatment device's life-cycle energy and CO2 profiles.
Characterization of bacterial biofilm communities in tertiary treatment processes for wastewater reclamation and reuse
Authors: Shoji Tadashi , Ochi Shuichi , Ozaki Masaaki
Published: October 2008

The concern with wastewater reuse as a sustainable water resource in urban areas has been growing. For the reclamation and distribution of wastewater, biofilm development deserves careful attention from the point of view of its promotion (e.g. biofiltration) and inhibition (e.g. clogging and hygiene problems). As the first step to control biofilm development, bacterial biofilm communities in tertiary treatment processes were characterized by using molecular biological methods. The result of clone library analysis showed that Nitrospirae-related (nitrite-oxydizing bacteria) and Acidobacteria-related (probably oligotrophic bacteria) groups were dominant. The ratio of the Nitrospirae-related group to the Acidobacteria-related group was associated with ammonia load, whereas other operational conditions (process, media, temperature, salt) did not clearly affect the phylum-level community or the dominant sequence of nitrifying bacteria. The result of real-time PCR also indicated that high ammonia load promotes the proliferation of nitrite- and ammonia-oxidizing bacteria. Regarding water supply systems, some researchers also have suggested the dominance of Nitrospirae- and Acidobacteria-related groups in biofilm formed on water distribution pipes. In tertiary wastewater treatment, therefore, it is concluded that oligotrophic and autotrophic bacteria are the dominant groups in biofilm samples because assimilable organic carbon is too poor to proliferate various heterotrophic bacteria.
Theoretical analysis on non-uniformity of water distribution and influence of construction parameters on settling efficiency
Authors: Huang Ting-Lin , Li Yu-Xian , Zhang Hui
Published: October 2008

During the reconstruction of horizontal flow tanks into inclined settling tanks in Chinese water plants, uniformity of water distribution has not been solved theoretically. Based on the concepts of hydraulics, a model of inclined tanks, including the ratio (L/B) of tank length (L) to width (B), diameter of inclined tubes (d) and height of the water distribution area (h1) and so on, was established to simulate and analyze the effects of these parameters on Non-Uniformity of Water Distribution (NUWD). The influences of NUWD on settling efficiency were also analyzed based on Yao's formula. Simulated results show that the ratio (L/B) has the greatest impact on NUWD, and the settling efficiency decreases with it. Under the conditions of q=10 or 20 m/h and L/B≥5 or 3, the total forces imposed on down-sliding flocs tend to be zero, which reduces the separating efficiency. Moreover, critical settling velocity (CSV) of the first inclined tube will decrease with the increase of h1, and the optimal range of h1 will be 1.2–1.6 m. The difference of CSV between the first tube and the average value of the tank u0 (shown as Δ(uF0−u0)) will increase with d and surface load (q).
Removal of arsenic from groundwater by arsenite-oxidizing bacteria
Authors: Ike M. , Miyazaki T. , Yamamoto N. , Sei K. , Soda S.
Published: October 2008

The presence of arsenic in groundwater has been of great public concern because of its high toxicity. For purification of arsenic-contaminated groundwater, bacterial oxidation of arsenite, As(III), with a chemical adsorption process was examined in this study. After As(III) oxidation to arsenate, As(V), arsenic is easily removable from contaminated groundwater because As(V) is more adsorptive to absorbents than As(III). By acclimation to As(III) of high concentrations, a mixed culture of heterotrophic bacteria with high As(III)-oxidizing activity was obtained from a soil sample that was free from contamination. With initial concentration up to 1,500 mg l−1 As(III), the mixed culture showed high As(III)-oxidizing activity at pH values of 7–10 and at temperatures of 25–35°C. The mixed culture contained several genera of heterotrophic As(III)-oxidizing and arsenic-tolerant bacteria: Haemophilus, Micrococcus, and Bacillus. Activated alumina was added to the basal salt medium containing 75 mg l−1 As(III) before and after bacterial oxidation. Arsenic removal by activated alumina was greatly enhanced by bacterial oxidation of As(III) to As(V). The isotherms of As(III) and As(V) onto activated alumina verified that bacterial As(III) oxidation is a helpful pretreatment process for the conventional adsorption process for arsenic removal.
Kinetics of growth and multi substrate degradation by an indigenous mixed microbial culture isolated from a wastewater treatment plant in Guwahati, India
Authors: Saravanan Pichiah , Pakshirajan K. , Saha P. K.
Published: October 2008

An indigenous mixed culture of microorganisms, isolated from a sewage treatment plant, was investigated for its potential to simultaneously degrade phenol and m-cresol during its growth in batch shake flasks. 22 full factorial designs with the two substrates as the factors, at two different levels and two different initial concentration ranges, were employed to carry out the biodegradation experiments. For complete utilisation of phenol and m-cresol, the culture took a minimum duration of 21 hrs at their low concentration of 100 mg/L each, and a maximum duration of 187 hrs at high concentration of 600 mg/L each in the multisubstrate system. The biodegradation results also showed that the presence of phenol in low concentration range (100–300 mg/L did not inhibit m-cresol biodegradation; on the other hand, presence of m-cresol inhibited phenol biodegradation by the culture. Moreover, irrespective of the concentrations used, phenol was degraded preferentially and earlier than m-cresol. During the culture growth, a lag phase was observed above a combined concentration of 500 mg/L i.e., 200 mg/L m-cresol and 300 mg/L of phenol and above). Statistical analysis of the specific growth rate of the culture in the multisubstrate system was also performed in the form of ANOVA and Student ‘t’ test, which gave good interpretation in terms of main and interaction effects of the substrates.