bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of Alloy Composition & Helium ion-irradiation on the Mechanical Properties of Tungsten, Tungsten-Tantalum & Tungsten-Rhenium for Fusion Power Applications
Authors: Beck Christian E. , Roberts Steve G. , Edmondson Philip D. , Armstrong David E. J.
Published: April 2013

Model alloys have been made of pure W and 1% & 5% W-Ta and W-Re. Indentation hardness and modulus data were obtained by nanoindentation to assess the effect of composition on mechanical properties. Results showed that both the Ta and Re compositions hardened with increasing alloy content, greater in the W-5%Ta composition which showed an increase of 1.03GPa (17%), compared to a 0.43GPa (7%) increase in W-5%Re. The samples also showed very small increases in modulus of ∼ 25GPa (6%) in both W-5%Re and W-5%Ta. The samples were implanted with 3000appm concentration of helium. All samples show a substantial increase in hardness of up to 107% in the case of pure W. An appreciable difference in modulus is also seen in all samples. Initial TEM work has shown no visible He bubbles, suggesting that the mechanical properties changes are due to He-vacancy cluster formation below the resolvable limit.
Variations of Internal Stresses within a Rafted Superalloy during High Temperature Mechanical Testing: An in situ XRD Study
Authors: Jacques Alain , Dirand Laura , Schenk Thomas , Chateau-Cornu Jean Philippe , Ferry Olivier , Bastie Pierre
Published: April 2013

Modeling of the mechanical behavior of a two-phased material, even with a simple microstructure such as a single crystal superalloy remains a difficult task, for lack of phase specific experimental data. The combination of Three Crystal Diffractometry with high energy synchrotron radiation and in situ experiments can give access to such data in real time. A few examples are given on load transfer between phases, dislocation densities, and the stress – strain behavior of a phase.
Phase Transformations in physical mixtures of Pd-Cu nanoparticles
Authors: Mukundan Vineetha , Yin Jun , Zhong Chuan-Jian , Malis Oana
Published: April 2013

The temperature induced structural transformations in physical mixtures of 1nm palladium and ultrafine (∼0.5nm) copper nanoparticles supported on carbon were studied using in-situ real time synchrotron based x-ray diffraction. These nanoparticles were subjected to two-step thermal annealing from 25°C to 700°C. The Pd and Cu nanoparticles were found to coalesce forming alloy nanoparticles that subsequently undergo a structural phase transformation from ordered B2 to disordered fcc. The random alloy formed at the end of the thermal treatments was found to be copper-rich.
Connecting accuracy of interchanged prosthetic abutments to different dental implants using scanning electron microscopy
Authors: Zanardi Piero Rocha , Costa Bruno , Stegun Roberto Chaib , Sesma Newton , Mori Matsuyoshi , Laganá Dalva Cruz
Published: April 2013

The present study evaluated the interchangeability of prosthetic components for external hexagon implants by measuring the precision of the implant/abutment (I/A) interface with scanning electron microscopy. Ten implants for each of three brands (SIN, Conexão, Neodent) were tested with their respective abutments (milled CoCr collar rotational and non-rotational) and another of an alternative manufacturer (Microplant) in randomly arranged I/A combinations. The degree of interchangeability between the various brands of components was defined using the original abutment interface gap with its respective implant as the benchmark dimension. Accordingly, when the result for a given component placed on an implant was equal to or smaller then that gap measured when the original component of the same brand as the implant was positioned, interchangeability was considered valid. Data were compared with the Kruskal-Wallis test at 5% significance level. Some degree of misfit was observed in all specimens. Generally, the non-rotational component was more accurate than its rotational counterpart. The latter samples ranged from 0.6-16.9 µm, with a 4.6 µm median; and the former from 0.3-12.9 µm, with a 3.4 µm median. Specimens with the abutment and fixture from Conexão had larger microgap than the original set for SIN and Neodent (p<0.05). Even though the latter systems had similar results with their respective components, their interchanged abutments did not reproduce the original accuracy. The results suggest that the alternative brand abutment would have compatibility with all systems while the other brands were not completely interchangeable.
Monomers used in resin composites: degree of conversion, mechanical properties and water sorption/solubility
Authors: Gajewski Vinícius E. S. , Pfeifer Carmem S. , Fróes-Salgado Nívea R. G. , Boaro Letícia C. C. , Braga Roberto R.
Published: April 2013

The organic phase of resin composites is constituted by dimethacrylate resins, the most common monomers being the bisphenol A diglycidildimethacrylate (BisGMA), its ethoxylated version (BisEMA), triethylene glycol dimethacrylate (TEGDMA) and urethane dimethacrylate (UDMA). This study compared the homopolymers formed from the monomers used in restorative dental composites in terms of their degree of conversion (DC) and reaction kinetics (by near infra-red spectroscopy, n=3), mechanical properties (flexural modulus and strength in three point-bending, FM and FS, respectively, n=15), water sorption and solubility (WS and SL, respectively - ISO 4049, n=5). Materials were made photopolymerizable by the addition of camphoroquinone/dimethylamine ethyl methacrylate. TEGDMA showed the highest DC, followed by BisEMA, UDMA and BisGMA, both at 10 min and at 24h (p<0.001). UDMA showed the highest rate of polymerization, followed by TEGDMA, BisEMA and BisGMA (H0=13.254, p<0.001). UDMA and TEGDMA presented similar FM, significantly higher (p<0.001) than BisEMA and BisGMA, which in turn present statistically similar values (p>0.001). For FS, UDMA presented the highest value (p<0.001), followed by TEGDMA, then by BisEMA and BisGMA, which were statistically similar (p>0.001). BisGMA showed the highest WS, and TEGDMA and BisEMA the lowest. UDMA was statistically similar to all (H0=16.074, p<0.001). TEGDMA presented the highest SL, followed by UDMA, BisGMA and BisEMA (p<0.001). The tested homopolymers presented different behaviors in terms of polymerization kinetics, flexural properties, water sorption and solubility. Therefore, the use of copolymers is justified in order to obtain high DC and mechanical properties, as well as good resistance to water degradation.
Adhesion of real seal to human root dentin treated with different solutions
Authors: Baldissera Renata , Rosa Ricardo Abreu da , Wagner Márcia Helena , Kuga Milton Carlos , Grecca Fabiana Soares , Bodanezi Augusto , Frasca Luis Carlos da Fontoura , Só Marcus Vinícius Reis
Published: April 2013

The aim of this study was to evaluate the effects of different irrigants on sealer-dentin bond strength when using Real Seal. Thirty single-rooted teeth were divided into 3 groups. In one group, the teeth were irrigated with 3 mL of 2.5% NaOCl after each file change, flushed with 17% EDTA for 3 min and finally rinsed with 3 mL of 2.5% NaOCl. In the other two groups, rinse with NaOCl was replaced with 2% chlorhexidine gluconate (CHX) and 0.9% saline, respectively. Each root was sectioned transversally into apical, middle and coronal thirds to obtain 2-mm-thick slices. Each slice was filled with Real Seal and Resilon. Push-out test was used to analyze bond strength and failure modes were classified as adhesive, cohesive or mixed, according to SEM observations. The push-out test did not reveal any statistically significant difference (p>0.05) between the irrigants. However, the groups exhibited significantly different (p<0.05) bond strengths in terms of the root canal third. Higher bond strength was observed at the apical third when compared with coronal third, while middle third presented intermediary values. Fifteen specimens were analyzed by SEM (5 per group). Eleven specimens exhibited adhesive failures (5 in saline, 4 in NaOCl and 2 in CHX group); 2 cohesive failures were observed in the CHX group, and 1 mixed failure each was observed in the CHX and NaOCl groups. The tested irrigants did not influence the bond strength of Resilon and Real Seal to dentin. The apical third exhibited higher mean bond strengths and adhesive failures were predominant.
In vitro genotoxicity and cytotoxicity in murine fibroblasts exposed to EDTA, NaOCl, MTAD and citric acid
Authors: Marins Juliana Soares Roter , Sassone Luciana Moura , Fidel Sandra Rivera , Ribeiro Daniel Araki
Published: April 2013

The aim of the present study was to evaluate the capacity of some root canal irrigants to induce genetic damage and/or cellular death in vitro. Murine fibroblast cells were exposed to ethylenediaminetetraacetic acid (EDTA), sodium hypochlorite (NaOCl), MTAD™ and citric acid in increasing concentrations for 3 h at 37ºC. The negative control group was treated with vehicle control (phosphate buffer solution - PBS) for 3 h at 37°C, and the positive control group was treated with methylmetanesulfonate, 1 μM. for 3 h at 37°C. Cytotoxicity was assessed by the trypan blue test and genotoxicity was evaluated by the single cell gel (comet) assay. The results showed that exposure to 2.5% and 5% NaOCl and 8.5% citric acid resulted in a significant cytotoxic effect. NaOCl, EDTA and citric acid did not produce genotoxic effects with respect to the comet assay data for all evaluated concentrations. Although MTAD was not a cytotoxic agent, it showed significant genotoxic effects at all tested concentrations (ANOVA and Tukey's test; p<0.05). NaOCl, EDTA and citric acid were found to be cytotoxic in a dose-dependent manner, but they were not genotoxic. MTAD did not cause cell death, but presented genotoxic effects.
Characterization of calcium oxide in root perforation sealer materials
Authors: Estrela Carlos , Sousa-Neto Manoel Damião , Guedes Orlando Aguirre , Alencar Ana Helena Gonçalves , Duarte Marco Antonio Hungaro , Pécora Jesus Djalma
Published: April 2013

Root perforation represents an undesirable complication that may lead to an unfavorable prognosis. The aims of this study were to characterize and to compare the presence of calcium oxide (CaO) on the chemical composition of materials used for root perforation therapy: gray and white mineral trioxide aggregate (MTA) and Portland cement (PC), gray MTA+5%CaO and gray MTA+10%CaO. The last two materials were analyzed to evaluate the increase of CaO in the final sample. CaO alone was used as a standard. Eighteen polyethylene tubes with an internal diameter of 3 mm and 3 mm in length were prepared, filled and then transferred to a chamber with 95% relative humidity and a temperature of 37ºC. The chemical compounds (particularly CaO) and the main components were analyzed by energy-dispersive X-ray microanalysis (EDX). EDX revealed the following concentrations of CaO: gray MTA: 59.28%, white MTA: 63.09%; PC: 72.51%; gray MTA+5%CaO: 63.48% and gray MTA+10%CaO: 67.55%. The tested materials presented different concentrations of CaO. Even with an increase of 5 and 10% CaO in gray MTA, the CaO levels found in the MTA samples were lower than those found in PC.
Healing of a tooth with an overinstrumented apex, extensive transportation and periapical lesion using a 5 mm calcium hydroxide apical plug: an 8-year follow-up report
Authors: Souza Ronaldo Araújo , Silva-Sousa Yara T. Corrêa , Colombo Suely , Lago Maurício , Duarte Marco Antonio Hungaro , Pécora Jesus Djalma
Published: April 2013

Besides the risk of filling material extrusion throughout the apex, a satisfactory apical seal can be difficult to achieve in canals with open apices or iatrogenic enlargements of the apical constriction. These situations pose a challenge to root canal filling. This paper describes the root canal filling of a maxillary right canine with an overinstrumented apex, complete loss of the apical stop, extensive canal transportation and apical periodontitis. A 5 mm calcium hydroxide apical plug was placed before root canal filling. The plug was made by soaking paper points with saline, dipping the points in calcium hydroxide powder and then applying it to the apex several times, until a consistent apical plug was obtained. The canal was then irrigated with saline in order to remove any residual calcium hydroxide from the root canal walls, dried with paper points and obturated with an inverted #80 gutta-percha cone and zinc oxide-eugenol based sealer by the lateral condensation technique. An 8-year radiographic follow-up showed formation of mineralized tissue sealing the apical foramen, apical remodeling and no signs of apical periodontitis.
When are fish sources vs. sinks of nutrients in lake ecosystems?
Authors: Vanni Michael J. , Boros Gergely , McIntyre Peter B.
Published: April 2013

Animals can be important in nutrient cycling through a variety of direct and indirect pathways. A high biomass of animals often represents a large pool of nutrients, leading some ecologists to argue that animal assemblages can represent nutrient sinks within ecosystems. The role of animals as sources vs. sinks of nutrients has been debated particularly extensively for freshwater fishes. We argue that a large pool size does not equate to a nutrient sink; rather, animals can be nutrient sinks when their biomass increases, when emigration rates are high, and/or when nutrients in animal carcasses are not remineralized. To further explore these ideas, we use a simple model to evaluate the conditions under which fish are phosphorus (P) sources or sinks at the ecosystem (lake) level, and at the habitat level (benthic and water column habitats). Our simulations suggest that, under most conditions, fish are sinks for benthic P but are net P sources to the water column. However, P source and sink strengths depend on fish feeding habits (proportion of P consumed from the benthos and water column), migration patterns, and especially the fate of carcass P. Of particular importance is the rate at which carcasses are mineralized and the relative importance of benthic vs. pelagic primary producers in taking up mineralized P (and excreted P). Higher proportional uptake of P by benthic primary producers increases the likelihood that fish are sinks for water column P. Carcass bones and scales are relatively recalcitrant and can represent a P sink even if fish biomass does not change over time. Thus, there is a need for better documentation of the fraction of carcass P that is remineralized, and the fate of this P, under natural conditions. We urge a more holistic perspective regarding the role of animals in nutrient cycling, with a focus on quantifying the rates at which animals consume, store, release, and transport nutrients under various conditions.
Massive Gingival Fibrous Lesion Excision Using Acellular Dermal Matrix for Gingival Regeneration: A Case Report
Authors: Eskan Mehmet Akif , Greenwell Henry
Published: April 2013

Introduction: Localized gingival fibrous lesions (GFLs) can be esthetically disfiguring and may be associated with specific local, systemic, or unknown factors. Treatment of GFLs includes wide excision of the lesion, followed by the often difficult task of restoring soft‐tissue function and esthetics. This case report describes the use of acellular dermal matrix (ADM) for wound coverage after lesion removal.

Case Presentation: A 50‐year‐old African‐American female presented with a very large, facially located, GFL between teeth #10 and #11. She reported that a similar lesion had been removed twice before this recurrence. No local irritants were noted that might be associated with this type of lesion. The lesion was excised, including periosteum, leaving a large area of denuded bone that was covered with ADM. This resulted in regeneration of the gingiva and provided an excellent esthetic outcome for the patient.

Conclusions: There was no evidence of recurrence of the lesion in the first 15 months. The etiology of the lesion is unknown, and it was difficult to classify histologically using the current classification system for these lesions. Using ADM improved postoperative pain management, facilitated healing of the denuded bone, and resulted in an acceptable functional and esthetic regeneration of the gingiva.
The Competence Part of a High Integrity Process
Authors: Lovell Sandra , Hill Peter
Published: April 2013

Managing operator competence is a critical part of managing overall safety of an asset. Wherever people interface with complex work systems, skilled performance and system knowledge are vital to operational integrity. Increasingly, regulators are demanding that operators demonstrate, through their safety case, how they are minimising the risk of human failure, from design of the asset through to operations. Key to managing this risk is a robust competence management system; one which provides an integrated set of safety critical operational activities and maintenance tasks carried out in the organisation.

Industry leaders agree that assurance of systematic process safety competence requires board-level ownership. Board members and senior leaders need to demonstrate and invest in good competence management practices at the individual level. They also need to know what processes and practices are vulnerable at any given moment.

Proactively managing process safety competence can be demonstrated through a Competency Management System, which incorporates recruitment requirements, site induction materials, training courses, risk assessment tools (e.g. HAZIDs, Bow-ties, HAZOPs), human error analyses and training needs analyses. The right merging of these to underpin competence is a critical part of a site’s overall management of major accident hazards.

This paper discusses the practicalities of building and refining a Competency Management System, to enable owners to better manage process safety through demonstrated competence.
Ten Golden Rules For Developing Robust Bowties
Authors: Ramsden Martyn , Taylor Mark , Steer Rob , Bennett Rachel
Published: April 2013

Ten rules are presented to assist in the development of robust bowtie diagrams, providing clarity, definition and guidance to ensure that the objectives of the study are met.

Bowtie diagrams are a well-established and increasingly widespread tool for risk management, providing a concise summary of a complex process safety situation. Experience of reviewing bowtie diagrams has made clear that the quality and depth of bowtie diagrams are extremely variable. These problems may stem from a lack of clarity around the objectives of the bowtie exercise, with no clear understanding of the ultimate use to which a bowtie will be put. Problems may also arise from a lack of understanding or loose definition of the various component parts of a bowtie. A lack of rigor identifying barriers may result in an overestimate of the strength and number of safeguards.

For this reason, ten ‘golden rules’ are presented for ensuring robust bowtie diagrams. These rules provide: clarification of the objectives of the exercise; guidance on choosing clear study boundaries; definition of the elements of bowties; and clarity on what constitutes a barrier. In addition the rules provide guidance about the incorporation of human factors; an area prone either to neglect or over-simplification.

Whilst the concept of a bowtie diagram is simple to grasp, producing bowties which are of a consistent standard is notoriously difficult. The rules presented in this paper provide a framework for standardizing and quality-checking bowties, with the intention of improving their effectiveness in managing major hazards.
Protoporphyrinogen Oxidase–Overexpressing Transgenic Rice is Resistant to Drought Stress
Authors: Yun Young Beom , Park Jong In , Choi Hyun Sug , Jung Ha‐il , Jang Se Ji , Back Kyoungwhan , Kuk Yong In
Published: April 2013

Transgenic rice (Oryza sativa L. ‘Dongjin’) lines, AP37 and MX, overexpressing Arabidopsis thaliana and Myxococcus xanthus protoporphyrinogen oxidase (PPO), respectively, were examined for their physiological responses and tolerance mechanism to drought stress. AP37 and MX lines were previously confirmed to be resistant to PPO inhibitors. Transgenic AP37 and MX plants showed significantly improved drought tolerance, as indicated by higher water content, lower leaf injury, less oxidative damage, and more favorable redox balance compared to wild‐type (WT) plants. The magnesium‐protoporphyrin IX (Mg‐Proto IX) content of WT and the transgenic lines did not vary significantly with the drought treatments, but MX lines had higher Mg‐Proto IX methyl ester (ME) content after 90 h of drought treatment compared to WT and AP37. In addition, the expression of most genes involved in porphyrin biosynthesis, particularly in the chlorophyll branch, such as glutamyl‐tRNA reductase, glutamate‐1‐semialdehyde aminotransferase, protoporphyrinogen oxidase 1, Fe‐chelatase2, H‐subunit of Mg‐chelatase, and I‐subunit of Mg‐chelatase, was up‐regulated in the transgenic plants, and this up‐regulation was higher in AP37 than in MX. Overall, the AP37 transgenic line was found to show better drought tolerance than the MX transgenic line.
Soybean Germplasm Resistant to Pythium irregulare and Molecular Mapping of Resistance Quantitative Trait Loci derived from the Soybean Accession PI 424354
Authors: Ellis Margaret L. , McHale Leah K. , Paul Pierce A. , St. Martin Steven K. , Dorrance Anne E.
Published: April 2013

Pythium irregulare Buisman is an important seed and seedling pathogen of many hosts including soybean [Glycine max (L.) Merr.] and has been increasingly linked to reports of stand losses. The objectives of this research were to identify sources of resistance to P. irregulare, characterize the type of resistance identified, and genetically map the resistance. Sixty‐five soybean genotypes were evaluated for resistance to two isolates of P. irregulare, and approximately one‐third had moderate to high levels of resistance. The PI 424354 had the highest levels of resistance to P. irregulare, and resistance was mapped in two three‐way cross populations: ‘OHS 303’ (moderately susceptible) × (‘Williams’ (moderately susceptible) × PI 424354) and ‘Dennison’ (moderately susceptible) × (Williams × PI 424354). Resistance quantitative trait loci (QTL) with alleles from PI 424354 were mapped on chromosomes 1 and 6 in OHS 303 × (Williams × PI 424354) using composite interval mapping (CIM) for root weights and root rot scores. Resistance QTL from PI 424354 were also mapped on chromosomes 8 and 11 with CIM for root weight data in the Dennison × (Williams × PI 424354) population and chromosome 13 using root rot scores. Each QTL explained 7.9 to 17.8% of the phenotypic variation. These are the first reported putative QTL for resistance to P. irregulare in soybean.
Relationship of Line per se and Testcross Performance for Grain Yield of Tropical Maize in Drought and Well‐Watered Trials
Authors: Kebede Aida Z. , Melchinger Albrecht E. , Cairns Jill E. , Araus José Luis , Makumbi Dan , Atlin Gary N.
Published: April 2013

To optimize the efficiency of maize (Zea mays L.) drought breeding, the ability to predict testcross performance (TP) under drought stress using line per se performance (LP) of the parental inbreds would be useful. We evaluated LP and TP of tropical inbreds in well‐watered and drought environments in Kenya and Mexico. Our main objective was to determine if LP under drought stress was predictive of TP for grain yield under drought stress and if selection for LP under drought stress would result in reduced yield potential for TP under well‐watered conditions. Average yield reduction under drought stress was 77% for lines and 68% for testcrosses. Average genotypic correlations between lines and testcrosses under drought stress were positive and low (genotypic correlation = 0.48), but correlations increased with increasing levels of drought stress in both LP and TP trials. Averaged over all sets, indirect selection for LP was predicted to be only 57% as effective as direct selection for TP under drought stress but was on average substantially higher in testcross sets where yield reduction due to drought was 70% or more. Therefore, LP under drought stress could be used to develop hybrids for severely drought‐prone environments. Moreover, LP under drought stress was uncorrelated with TP for grain yield under well‐watered conditions, showing that selection of lines per se for drought tolerance would likely not reduce yield potential of testcrosses.
Coefficient of Parentage in Coffea arabica L. Cultivars Grown in Brazil
Authors: Setotaw Tesfahun Alemu , Caixeta Eveline Teixeira , Pereira Antônio Alves , de Oliveira Antonio Carlos Baião , Cruz Cosme Damião , Zambolim Eunize Maciel , Zambolim Laércio , Sakiyama Ney Sussumu
Published: April 2013

The coefficient of parentage among 121 cultivars of Coffea arabica L. in Brazil released from 1939 to 2009 was estimated and used to study the genetic diversity and the breeding pattern of the breeding programs. A low genetic diversity was observed within the C. arabica cultivars of Brazil. The genetic base of 121 cultivars released in Brazil between 1939 and 2009 was defined by 13 ancestors. Seven ancestors contribute with 97.55% of the genetic base of C. arabica cultivars. Bourbon Vermelho contributed with 52.76% for the genetic pool of the C. arabica cultivars of Brazil followed by Sumatra (19.05%) and Híbrido de Timor (11.59%). Mundo Novo and Icatu Vermelho contributed with 87.65% for the genetic base of the C. arabica cultivars. It was calculated that 97.55% of the genetic base of the Brazilian C. arabica cultivars is derived from seven ancestors, indicating a narrow genetic base. Among the first progenies, Mundo Novo contributed with 69.39% of the genetic base of C. arabica cultivars in Brazil. The increase in the genetic diversity among C. arabica cultivars observed in recent decades is due to the introduction of parental lines with diverse genetic base. High genetic diversity was observed among cultivars released by Empresa de Pesquisa Agropecuária de Minas Gerais/Universidade Federal de Viçosa, Fundação Procafé, and Instituto Agronômico do Paraná. The 121 Brazilian cultivars were clustered into four groups based on coefficient of parentage. The distributions of genotypes over the cluster groups showed the effect of parental line contribution.
Influence of Three Nitrogen Fertilization Schedules on Bermudagrass and Seashore Paspalum: II. Carbohydrates and Crude Protein in Stolons
Authors: Rimi Filippo , Macolino Stefano , Richardson Michael D. , Karcher Douglas E. , Leinauer Bernd
Published: April 2013

In the transition zone, a primary concern in managing warm‐season turfgrasses is turf survival under low temperatures. The objectives of this study were to determine the effects of three N fertilization schedules on stolon carbohydrates and crude protein (CP) reserves of four bermudagrasses [Cynodon dactylon (L.) Pers.] and a seashore paspalum (Paspalum vaginatum Sw.). A field trial was performed at the agricultural experimental farm of Padova University (northeastern Italy). Bermudagrass cultivars Princess‐77, Riviera, SWI 1014, and Yukon and seashore paspalum ‘Sea Spray’ were compared under three N fertilization schedules: (i) 6.7 g N m–2 on 15 May, 15 June, and 15 August, (ii) 5 g N m–2 on 15 May, 15 June, 15 August, and 15 October, and (iii) 4 g N m–2 on 15 May, 15 June, 15 August, 15 September, and 15 October. Turf samples measuring 20 by 20 by 4 (depth) cm were collected monthly from September to April 2009 to 2010 and 2010 to 2011. The stolons were separated from the remainder of the samples and starch, water‐soluble carbohydrates (WSC), and CP were determined on a dry matter basis. The bermudagrass cultivar Riviera was characterized by high stolon density and showed highest carbohydrates (starch and WSC) content along with Yukon. Late‐season applications of N had limited influence on carbohydrates content but increased the concentrations of CP from November through April.
Designing sustainable sanitation in urban planning proposed for Changzhou, China
Authors: Kerstens S. M. , de Mes T. Z. D. , Lue B.
Published: April 2013

China is undergoing rapid urbanization and economic development. This requires a new approach on spatial planning and environmental infrastructure. In the presented project an example of this approach is given for the city of Changzhou (China) where a new residential area (Qinglong district) will be developed for 100.000 inhabitants. Key issue within the formulation of sustainable sanitation concepts is the integration and management of water, waste and energy in such a way that they will become beneficial to the establishment of the envisaged green city. Starting point was the closing of material cycles focusing on possibilities to recover and reuse valuable resources and energy from “waste” produced in an urban setting. Four different scenarios focusing on water, nutrient and energy recovery were compared with the baseline wastewater management practice. Besides environmental benefits, the economical benefits of sustainable sanitation concepts are attractive, the break even point with the baseline scenario, is already after 5 years, provided that recovered resources will be sold for a marketable price. We believe that presented concepts are applicable for a wide range of new urban development initiatives in China and similar rapidly developing densely populated regions worldwide.
Efficient and integrated start-up strategy for partial nitrification to nitrite treating low C/N domestic wastewater
Authors: Guo Jianhua , Wang Shuying , Huang Huijun , Peng Yongzhen , Ge Shijian , Wu Changyong , Sun Zhirong
Published: April 2013

Nitrogen removal via the nitrite pathway has the potential of reducing the requirements for aeration consumption and carbon source. However, the development of an efficient and quick start-up strategy for partial nitrification to nitrite has proven difficult in the treatment of low strength wastewater. In this study, the feasibility of partial nitrification achieved by using real-time aeration duration control was not only demonstrated from the kinetic mechanism, but also was validated in three sequencing batch reactors (SBRs) fed with low C/N domestic wastewater. Nitrite accumulation could be achieved when aeration was terminated as soon as an inflexion pH point was reached (the dpH/dt became from negative to positive). The reduction or limitation of the NOB growth could be achieved through aeration duration control, due to leaving no extra time for NOB to convert the accumulated nitrite. The experimental operation results also showed that partial nitrification with nitrite accumulation ratios of over 80% was achieved successfully in these three reactors with process control. Fluorescence in situ hybridization (FISH) analysis indicated the reduction of NOB was achieved and AOB became the dominant nitrifying bacteria. Moreover, an integrated start-up strategy based on aeration duration control was proposed to quickly achieve partial nitrification to nitrite.
Full activated sludge model no. 1 calibration experience at a medium-size WWTP in Mexico
Authors: Fall C. , Loaiza-Navia J. , Esparza-Soto M.
Published: April 2013

As part of the efforts done to introduce the practice of modeling in Latin America, this research carried out at the North-East WWTP of Monterrey represents the first comprehensive modeling case in Mexico. The main objective was to reproduce the organic carbon removal and sludge production rates of the plant, based on ASM1. Different intermediate studies were performed prior to the calibration of the model: influent characterization, tracer tests and hydraulics modeling, sludge settling tests and respirometry. Two fractionation methods (STOWA protocol and Influent-advisor) were compared, showing no equivalent patterns. A stepwise sequence of calibration was developed and successfully applied. The hydraulics of the reactors at the plant was reproduced by use of a series of 3 to 5 CSTRs. The waste and return activated sludge flowrates (QWAS and QRAS) were corrected based on the inorganic and total suspended solids mass balances. The Vesilind settling constants were measured (Vo and rhind), while the flocculent zone settling parameter (rfloc) was adjusted to calibrate the secondary clarifier. In ASM1, the adjusted parameters were the COD soluble inert fraction (frSI) and the particulate substrate fraction (FrXS). All other ASM1 parameters were kept at their default values. The steady-state calibrated model (in GPS-X) adequately described the quality of the effluent (carbon and nitrogen) as well as the sludge composition (M. Liquor and WAS). This case study provides voluntarily detailed data to allow its wide use for training and teaching purposes.
Pilot study of a submerged membrane bioreactor for water reclamation
Authors: Qin Jian-Jun , Oo Maung Htun , Tao Guihe , Kekre Kiran A. , Hashimoto Tomotaka
Published: April 2013

The objective of this pilot study was to investigate the operational conditions of newly developed MBR modules for water reclamation under tropical conditions. MUDC-620A MBR modules with hollow fibre PVDF membranes from Asahi-Kasei Chemicals were used in the study. The pilot plant with capacity of 50 m3/d was operated continuously (24-hour) over four months on site of Ulu Pandan Water Reclamation Plant (UPWRP) in Singapore. During the study, the MLSS in membrane tank was in the range of 6,840 ∼ 9,540 mg/L. Filtration operation mode of the membrane unit was 9 minutes on production and 1 minute backwash. The air scouring for the membranes was 0.18–0.30 Nm3/h per m2 membrane area all of the time. Trials on different membrane fluxes were conducted to obtain the sustainable flux. The analytical results showed that COD, TOC, T-N and NH4-N of the treated water were <30 mg/L, 5–7 mg/L, <13 mg/L and <0.1 mg/L, respectively, which met the requirement of Industrial Water for reuse. TMP was in the range of 12–40 kPa and could be recovered after cleaning with 2,000 mg/L sodium hypochlorite solution. Sludge clogging could be a challenge for long-term operation with the current module design. It was concluded that it was feasible for MUDC-620A MBR to operate at a net flux of 25–29 LMH (or 0.6–0.7 m/d) for treating the municipal wastewater at UPWRP.
Active manganese oxide: a novel adsorbent for treatment of wastewater containing azo dye
Authors: Chakrabarti S. , Dutta B. K. , Apak R.
Published: April 2013

A new variety of active manganese oxide was prepared, characterized, and tested for its potential of adsorbing Congo Red, a dis-azo dye, from aqueous solutions. Both equilibrium and kinetics were investigated over different values of process parameters such as temperature (25–45°C), adsorbent loading (0.4–0.6%), initial dye concentration (50–500 mg/L), presence of salts (sodium sulphate, 500 mg/L) and the oxygen content (MnOx, x = 1.2, 1.33 and 2) of the adsorbent. The equilibrium adsorption data were fitted to Langmuir and Freundlich isotherms. Langmuir adsorption capacity of the sorbent (x = 1.33) for Congo Red was 38.6 mg/g at room temperature which is substantially higher than those for commercial manganese dioxide, red mud, coir pith, activated carbon, and fly ash. The kinetic data were best interpreted using a pseudo-second order model. The results show that the active manganese oxide used in this work removes the dye by reversible adsorption and has the potential for practical use for remediation of textile industry effluents.
A study on the relationship between BOD5 and COD in coastal seawater environment with a rapid BOD measurement system
Authors: Jin X. L. , Jing M. , Chen X. , Zhuang Z. X. , Wang X. R. , Lee Frank S. C.
Published: April 2013

The dual objectives of this study are to: (1) examine the relationship between COD and BOD in seawater environment with a rapid but reliable method for the measurement of BOD in seawater, and (2) establish the relationship model between BOD5 and COD in the firth of Dongbao River to predict the values of BOD5. The first objective is met by the successful development of a technique utilizing bacteria-immobilized membrane flow cell for biodegradation process, coupled with fibre optic fluorescence detection for oxygen depletion quantitation. The technique has been applied to coastal seawater samples collected in the coastal area of Shenzhen, China. The BOD5 and COD values for the samples are acquired and the results show that there is no apparent linear relationship existing between BOD5 and COD in relatively clean seawater samples away from the shore. However, in estuary water samples containing relatively high concentration of sewage contamination, a linear correlation does exist between BOD5 and COD. The linear relationship between the two parameters allows for the calculation of BOD5 values based on COD data which can be measured more readily and precisely.
An efficient GTS allocation scheme for IEEE 802.15.4 MAC layer
Authors: Huang Der-Chen , Lee Yi-Wei , Wu Hsiang-Wei
Published: April 2013

Based on IEEE 802.15.4, the contention-free period (CFP) adopts a guarantee
time slot (GTS) mechanism to ensure each device can access the radio
channel. However, it is hard to get the authority to access the radio
channel due to more competitor access the radio channel simultaneously. To
cope with this issue, we proposed a guarantee time slot mechanism to enhance
the performance and utilization by using CFP. Our proposed method ensures
each device has the authority to access the radio channel without any
additional step. By comparing with the method of IEEE 802.15.4, the
experimental results show that data average transmission delay and energy
consumption can be reduced dramatically. In addition, the bandwidth and
performance of network is improved since the pre-allocation mechanism can
reduce the number of control packets. Several experiments have been
conducted to demonstrate the performance of our work.
Two-step hierarchical scheme for detecting detoured attacks to the web server
Authors: Choi Byungha , Cho Kyungsan
Published: April 2013

In this paper, we propose an improved detection scheme to protect a Web
server from detoured attacks, which disclose confidential/ private
information or disseminate malware codes through outbound traffic. Our scheme
has a two-step hierarchy, whose detection methods are complementary to each
other. The first step is a signature-based detector that uses Snort and
detects the marks of disseminating malware, XSS, URL Spoofing and information
leakage from the Web server. The second step is an anomaly-based detector
which detects attacks by using the probability evaluation in HMM, driven by
both payload and traffic characteristics of outbound packets. Through the
verification analysis under the attacked Web server environment, we show that
our proposed scheme improves the False Positive rate and detection efficiency
for detecting detoured attacks to a Web server.
Traffic deflection method for dos attack defense using a location-based routing protocol in the sensor network
Authors: Kang Ho-Seok , Kim Sung-Ryul , Kim Pankoo
Published: April 2013

As the ubiquitous computing environment gets more attention and development,
WSN (Wireless Sensor Network) is getting popular as well. Especially, the
development of wireless communication and sensor equipment greatly
contributes to the popularization of WSN. On the other hand, the safety and
security of WSN attracts lots of attention due to such a development and
distribution. The DoS (Denial of Service) attack, which gets more
sophisticated and broadens its domain into various services fields, may have
negative effects on WSN, making it vulnerable to attacks. Since WSN collects
information through sensors that are already deployed, it is difficult to
have its energy recharged. When WSN is under a DoS attack, sensor nodes
consume lots of energy, bringing about a fatal result to the sensor network.
In this paper, we propose a method to efficiently defend against DoS attacks
by modifying routing protocols in the WSN. This method uses a location based
routing protocol that is simple and easy to implement. In the WSN environment
where the location-based routing protocol is implemented, this method
disperses the DoS attack concentration of traffic by using the traffic
deflection technique and blocks it out before arriving at the target
destinations. To find out the number of traffic redirection nodes proper for
this method, we have performed a few experiments, through which the number of
such nodes was optimized.
Benefiting from the community structure in opportunistic forwarding
Authors: Bai Bing , Feng Zhenqian , Zhao Baokang , Su Jinshu
Published: April 2013

In Delay Tolerant Networks (DTNs), an end-to-end connectivity cannot be
assumed for node mobility and lack of infrastructure. Due to the uncertainty
in nodal mobility, routing in DTNs becomes a challenging problem. To cope
with this, many researchers proposed opportunistic routing algorithms based
on some utilities. However, these simple metrics may only capture one facet
of the single node?s mobility process, which cannot reflect the inherent
structure of the networks well. Recently, some researchers introduce the
Complex network analysis (CNA) to formulate and predict the future contact in
DTNs. The community structure is one of the most important properties of CNA.
And it reveals the inherent structure of the complex network. In this paper,
we present a community-based single-copy forwarding protocol for DTNs
routing, which efficiently utilizes the community structure to improve the
forwarding efficiency. Simulation results are presented to support the
effectiveness of our scheme.
Efficient implementation for QUAD stream cipher with GPUs
Authors: Tanaka Satoshi , Nishide Takashi , Sakurai Kouichi
Published: April 2013

QUAD stream cipher uses multivariate polynomial systems. It has provable
security based on the computational hardness assumption. More specifically,
the security of QUAD depends on hardness of solving non-linear multivariate
systems over a finite field, and it is known as an NP-complete problem.
However, QUAD is slower than other stream ciphers, and an efficient
implementation, which has a reduced computational cost, is required. In this
paper, we propose an efficient implementation of computing multivariate
polynomial systems for multivariate cryptography on GPU and evaluate
efficiency of the proposal. GPU is considered to be a commodity parallel
arithmetic unit. Moreover, we give an evaluation of our proposal. Our
proposal parallelizes an algorithm of multivariate cryptography, and makes it
efficient by optimizing the algorithm with GPU.
Efficient verifiable fuzzy keyword search over encrypted data in cloud computing
Authors: Wang Jianfeng , Ma Hua , Tang Qiang , Li Jin , Zhu Hui , Ma Siqi , Chen Xiaofeng
Published: April 2013

As cloud computing becomes prevalent, more and more sensitive data is being
centralized into the cloud by users. To maintain the confidentiality of
sensitive user data against untrusted servers, the data should be encrypted
before they are uploaded. However, this raises a new challenge for performing
search over the encrypted data efficiently. Although the existing searchable
encryption schemes allow a user to search the encrypted data with
confidentiality, these solutions cannot support the verifiability of
searching result. We argue that a cloud server may be selfish in order to
save its computation ability or bandwidth. For example, it may execute only a
fraction of the search and returns part of the searching result. In this
paper, we propose a new verifiable fuzzy keyword search scheme based on the
symbol-tree which not only supports the fuzzy keyword search, but also enjoys
the verifiability of the searching result. Through rigorous security and
efficiency analysis, we show that our proposed scheme is secure under the
proposed model, while correctly and efficiently realizing the verifiable
fuzzy keyword search. The extensive experimental results demonstrate the
efficiency of the proposed scheme.
Design and implementation of an efficient and programmable future internet testbed in Taiwan
Authors: Hu Jen-Wei , Yang Chu-Sing , Liu Te-Lung
Published: April 2013

Internet has played an important part in the success of information
technologies. With the growing and changing demands, there are many
limitations faced by current Internet. A number of network testbeds are
created for solving a set of specific problems in Internet. Traditionally,
these testbeds are lacking of large scale network and flexibility. Therefore,
it is necessary to design and implement a testbed which can support wide
range of experiments and has the ability of programmable network. Besides,
there has been a big change enabled by cloud computing in recent years.
Although networking technologies have lagged behind the advances in server
virtualization, the networking is still an importance component to
interconnect among virtual machines. There are also measurement issues with
growing number of virtual machines in the same host. Therefore, we also
propose integrating management functions of virtual network in our testbed.
In this paper, we design and create a Future Internet testbed in Taiwan over
TWAREN Research Network. This testbed evolves into an environment for
programmable network and cloud computing. This paper also presents several
finished and ongoing experiments on the testbed for multiple aspects
including topology discovery, multimedia streaming, and virtual network
integration. We will continue to extend our testbed and propose innovative
applications for the next generation Internet.
Reconceptualising Family: Negotiating Sexuality in a Governmental Climate of Neoliberalism
Authors: Davies Cristyn , Robinson Kerry H.
Published: April 2013

Based on qualitative research, this article examines the complex kinship relations involved in constructing queer families. The discussion focuses on the heterogeneity of queer families; the difficulties encountered in association with processes of recognition and how this is negotiated across different contexts within queer families, extended families, and bureaucracies; how sexual subjectivities are articulated within the context of ‘family’; and concerns raised by queer families in relation to children's early schooling. Of particular importance to this discussion is awareness that in a governmental climate of neoliberalism, there are contradictory and competing discourses about queer subjectivities, the child, and constructions of family. The queer subject is frequently and increasingly positioned as a targeted consumer and this consumption extends to accessing foster care, adoption, reproductive technologies, the healthcare system, and education. However, despite the invitation to queer families to be consumers in these contexts, the normative family is still viewed as heterosexual, with queer families continuing to be excluded and rendered invisible in representations of family. Taking up Jonathan Silin's earlier call to educators of young children, the authors argue that children's early education needs to include difficult knowledge and subjugated knowledges. Early education should include knowledge about different kinds of kinship relations including queer families, non-biological formations of family, including fostering and adoption, and alternative reproductive practices and technologies through which many young children are now conceived. Currently, most early childhood education and primary school curricula in Australia do not reflect the reality of many young children's lives. Educating all children and youth about alternative families and sexuality is critical to children becoming socially informed citizens and politically active members of their communities who can participate in creating alternative and more equitable futures.