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Simultaneous nitrification and autotrophic denitrification in fluidized bed reactors using pyrite and elemental sulfur as electron donors

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Water Science and Engineering 2023年第2期16卷 143-153页

作者： Maria F.Carboni Sonia Arriaga piet n.l.len. national University of Ireland Galway H91 TK33 GalwayIreland Instituto Potosino de Investigación Científica y Tecnológica 78216 San Luis PotosíMexico

In this study, simultaneous nitrification and autotrophic denitrification (SnAD) with either elemental sulfur or pyrite were investigated in fluidized bed reactors in mesophilic conditions. The reactor performance was evaluated at different ammonium (12-40 mg/l of nH4+-n), nitrate (35-45 mg/l of nO3--n), and dissolved oxygen (DO) (0.1-1.5 mg/l) concentrations, with a hydraulic retention time of 12 h. The pyrite reactor supported the SnAD process with a maximum nitrogen removal efficiency of 139.5 mg/(l·d) when the DO concentration was in the range of 0.8-1.5 mg/l. This range, however, limited the denitrification efficiency of the reactor, which decreased from 90.0% ± 5.3% in phases II-V to 67.9% ± 7.2% in phases VI and VII. Sulfate precipitated as iron sulfate (FeSO4/Fe2(SO4)3) and sodium sulfate (na2SO4) minerals during the experiment. The sulfur reactor did not respond well to nitrification with a low and unstable ammonium removal efficiency, while denitrification occurred with a nitrate removal efficiency of 97.8%. In the pyrite system, the nitrifying bacterium nitrosomonas sp. was present, and its relative abundance increased from 0.1% to 1.1%, while the autotrophic denitrifying genera Terrimonas, Ferruginibacter, and Denitratimonas dominated the community. Thiobacillus, Sulfurovum, and Trichlorobacter were the most abundant genera in the sulfur reactor during the entire experiment.

关键词： Pyrite Elemental sulfur Simultaneous nitrification and denitrification nitrogen removal 16S rRnA

UnIFORMITY ASSESSMEnT OF CARBOn FIBRES DISPERSIOn In CEMEnT PASTE BY IMPEDAnCE MEASUREMEnTS

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Journal of Wuhan University of Technology(Materials Science) 1999年第1期14卷 52-57页

作者： Shui, Zhonghe Stroeven, piet Wuhan Univ Technol Coll Mat Sci & Technol Wuhan 430070 Peoples R China Delft Univ Technol Fac Civil Engn NL-2600 AA Delft Netherlands

An alternating current was applied to measure the impedance of a hardened cement paste with various contents of carbon fibres. When the free water content in the hardened cement paste is 90%-98%, and the measuring frequency 500 Hz, an approximate linear relationship was found between fibre content and impedance of the composite. Based on this relationship, a new attempt was made to evaluate the dispersion uniformity of carbon fibres in cement paste by impedance measurement. The standard deviation S and the coefficient of vriation S/X over bar //i of impedance of the fibre-cement specimens randomly taken locating in different points were used as main parameters for the uniformity assessment. As a case, four different mixing processes were designed for dispersing carbon fibres into the cement paste. The results demonstrate that the relative longer mixing time increases the dispersion uniformity of carbon fibres in cement paste, and the addition of the water reducer dramatically improves the uniformity due to the change of the fluidity of the paste. The ground fly ash can increase the uniformity to a certain extent. (Author abstract) 6 Refs.

关键词： carbon fibers uniformity assessment fiber concrete

Discrete element modelling approach to assessment of granular properties in concrete

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2011年第5期12卷 335-344页

作者： piet STROEVEn Huan HE Martijn STROEVEn Faculty of Civil Engineering and Geosciences Delfi University of Technology Stevimveg 1 2628 CN Delft the Netherlands Faculty of Applied Sciences University of Liege Chemin des Chevreuils 1 4000 Liege Belgium

This paper presents the technological relevance of a concurrent algorithm-based discrete element modelling (DEM) system, HADES. This new system is the successor of SPACE that is limited to spherical grains only. It can realistically simulate the packing of arbitrary-shaped particles up to the fully compacted state. Generation of families of such particles, i.e., generally representing aggregate of fluvial origin and crushed rock, respectively, and the forming way of particulate structure are described. Similarly shaped particles are proposed for simulation of cement paste because of conformity with experimental results obtained by the X-ray tomography method. Technologically relevant territories inside and outside concrete technology are presently explored in this efficient, reliable, and economic way. Some results obtained by this DEM approach are presented.

关键词： Cementitious materials Granular properties Concurrent algorithm Discrete element modelling (DEM) Shape Particles

Unifying concepts in methanogenic,aerobic,and anammox sludge granulation

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Environmental Science and Ecotechnology 2024年第1期17卷 17-30页

作者： Simon Mills Anna Christine Trego Marco Prevedello Jo De Vrieze Vincent O’Flaherty piet n.l.len. Gavin Collins Microbial Communities laboratory School of Biological and Chemical SciencesNational University of Ireland GalwayUniversity RoadGalwayH91 TK33Ireland Microbial Ecology laboratory School of Biological and Chemical Sciences University of GalwayUniversity RoadGalwayH91 TK33Ireland Center for Microbial Ecology and Technology(CMET) Ghent UniversityCoupure Links 653B-9000GentBelgium University of Galway University RoadGalwayH91 TK33Ireland

The retention of dense and well-functioning microbial biomass is crucial for effective pollutant removal in several biological wastewater treatment *** solids retention is often achieved through aggregation of microbial communities into dense,spherical aggregates known as granules,which were initially discovered in the *** granules have since been widely applied in upflow anaerobic digesters for waste-to-energy ***,granular biomass has been applied in aerobic wastewater treatment and anaerobic ammonium oxidation(anammox)*** mechanisms underpinning the formation of methanogenic,aerobic,and anammox granules are the subject of ongoing *** each granule type has been extensively studied in isolation,there has been a lack of comparative studies among these granulation *** is likely that there are some unifying concepts that are shared by all three sludge *** these unifying concepts could allow a unified theory of granulation to be ***,we review the granulation mechanisms of methanogenic,aerobic,and anammox granular sludge,highlighting several common concepts,such as the role of extracellular polymeric substances,cations,and operational parameters like upflow velocity and shear *** have then identified some unique features of each granule type,such as different internal structures,microbial compositions,and quorum sensing ***,we propose that future research should prioritize aspects of microbial ecology,such as community assembly or interspecies interactions in individual granules during their formation and growth.

关键词： Granule Granulation Anaerobic digestion Anammox Aerobic granule

Distribution and fate of metals in the Montenegrin part of lake Skadar

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International Journal of Sediment Research 2014年第3期29卷 357-367页

作者： Mirjana VEMIC Diederik ROUSSEAU Gijs DU lAInG piet lenS UnESCO-IHE Institute for Water Education Department of Environmental ResourcesP.O.Box 30152601 DADelftThe Netherlands University College West Flanders EnBiChem research groupGraaf Karel de Goedelaan 58500 KortrijkBelgium 3. Laboratory of Analytical Chemistry and Applied EcochemistryGhent UniversityFaculty of Bioscience EngineeringCoupure Links 653B-9000 GhentBelgium 4. UNESCO-IHE Institute for Water EducationDepartment of Environmental ResourcesP.O.Box 30152601 DA DelftThe Netherlands

Skadar lake,the largest lake on the Balkan Peninsula,is famous for a wide range of endemic and rare,or even endangered plant and animal *** anthropogenic pressures have,however,influenced the fragile equilibria of the lake ecosystem,with metal pollution as one of the primary ***,this study investigated spatial distribution of metal pollutants in the water and sediment phase of Skadar lake,and anthropogenic and environmental factors affecting this distribution.A sieving analysis showed that sediment in Skadar lake is mainly distributed in the three smallest fractions(colloid,clay and silt).Eleven metals were analyzed in the lake surface and bottom water,and only six of them were detected:potassium,magnesium,calcium,nickel,aluminum and *** were all present at low *** contrast,sediments contained elevated levels of some metals with concentrations between 28.1-126.8 mg kg-1for ni,23.6-79.2 mg kg-1for Cr,9.2-36.9 mg kg-1for Cu,199-878 mg kg-1for Mn and 9.6-23.1 g kg-1for *** exceeded consensus-based guidelines for safety towards freshwater dwelling *** organic matter content of the sediment fluctuated between 4.7 and 21.5%.no correlations were found between metal concentrations,organic matter and sediment particle size fractions,suggesting that the latter are not the main factors controlling metal accumulation in Skadar lake.

关键词： Skadar lake nickel contamination Metal pollution Spatial distribution of metals

Intermediate Energy Pion-^(20)ne Elastic Scattering in the α+^(16)O Model of (20)~ne

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Communications in Theoretical Physics 2013年第11期60卷 588-592页

作者：杨永栩 Ong piet-Tjing 李清润 Department of Physics Guangxi Normal University Institute of High Energy Physics Chinese Academy of Sciences

We present an analysis of π-^20ne elastic scattering at intermediate energy basing on the α＋^16O model of the ^20ne nucleus and in the framework of Glauber multiple scattering theory. Satisfactory agreement with the general features of the experimental data of pion elastic scattering on the neighboring 4n-type nuclei is obtained without any free parameters. Compared with the experimental angular distributions of pion elastic scattering on ^12 C, ^16O, ^24Mg, and ^28Si nuclei, the diffractive patterns and the positions of the dips and peaks in the angular distributions of ^π-^20ne elastic scattering are reasonably predicted by the calculations.

关键词： pion-nucleus elastic scattering nuclear cluster model

Hyaluronan as an immunological adjuvant:a novel application for an ancient molecule

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Cellular & Molecular Immunology 2023年第10期20卷 1251-1253页

作者： D.Carpanese A.Dalla pietà A.Rosato Veneto Institute of Oncology IOV-IRCCS PadovaItaly University of Padua Department of SurgeryOncology and GastroenterologyPadovaItaly

Vaccines are among the most important scientific breakthroughs in human ***,both the recent COVID-19 pandemic and cancer prevalence highlighted the requirements for new vaccination platforms that are more effective in stimulating complex immune responses,including the activation of CD4^(+)and CD8+T-cell-mediated immunity and the induction of immunological *** this regard,protein-/peptide-based vaccines represent valuable options that are based on a balance between a good safety profile and a relatively rapid manufacturing time;nonetheless,efficient adjuvants are needed for protein-based vaccines to overcome weak ***-like receptor(TlR)agonists have been advanced as promising adjuvants for the development of protein-based vaccines that can overcome all the shortcomings of clinically available formulations,as these agonists fine-tune the crosstalk between innate and adaptive immune ***,a critical challenge remains the identification of TlR-agonist adjuvants with increased potency but minimal *** this context,natural polymers(nPs)and their derivatives originating from plants,animals,or microbes are good candidates for use in the creation of vaccines with both high safety and efficacy profiles[1].

关键词： adjuvant immunity overcome

Performance Characterization of Game Recommendation Algorithms on Online Social network Sites

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Journal of Computer Science & Technology 2012年第3期27卷 611-623页

作者： Philip leroux Bart Dhoedt piet Demeester Filip De Turck Department of Information Technology Interdisciplinary Institute for Broadband Technology(IBBT) Ghent UniversityG.Crommenlaan 8/201B-9050 GentBelgiumStudent MemberIEEE Department of Information Technology Interdisciplinary Institute for Broadband Technology(IBBT) Ghent UniversityG.Crommenlaan 8/201B-9050 GentBelgiumMemberIEEE Department of Information Technology Interdisciplinary Institute for Broadband Technology(IBBT) Ghent UniversityG.Crommenlaan 8/201B-9050 GentBelgiumFellowIEEE Department of Information Technology Interdisciplinary Institute for Broadband Technology(IBBT) Ghent UniversityG.Crommenlaan 8/201B-9050 GentBelgiumSenior MemberIEEE

Since years, online social networks have evolved from profile and communication websites to online portals where people interact with each other, share and consume multimedia-enriched data and play different types of games. Due to the immense popularity of these online games and their huge revenue potential, the number of these games increases every day, resulting in a current offering of thousands of online social games. In this paper, the applicability of neighborhood-based collaborative filtering （CF） algorithms for the recommendation of online social games is evaluated. This evaluation is based on a large dataset of an online social gaming platform containing game ratings （explicit data） and online gaming behavior （implicit data） of millions of active users. Several similarity metrics were implemented and evaluated on the explicit data, implicit data and a combination thereof. It is shown that the neighborhood-based CF algorithms greatly outperform the content-based algorithm, currently often used on online social gaming websites. The reslflts also show that a combined approach, fie, taking into account both implicit and explicit data at the same time, yields overall good results on all evaluation metrics for all scenarios, while only slightly performing worse compared to the strengths of the explicit or implicit only approaches. The best performing algorithms have been implemented in a live setup of the online game platform.

关键词： mining method and algorithm data mining personalization

Primary prevention and treatment of venous thromboembolic events in patients with gastrointestinal cancers- Review

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World Journal of Gastrointestinal Oncology 2016年第3期8卷 258-270页

作者： Hanno Riess piet Habbel Anja Jühling Marianne Sinn Uwe Pelzer Department of Hematology Oncology and Tumor Immunology Charité University Medicine Berlin

Venous thromboembolism event(VTE) is a common and morbid complication in cancer patients. Patients with gastrointestinal cancers often suffer from symptomatic or incidental splanchnic vein thrombosis, impaired liver function and/or thrombocytopenia. These characteristics require a thorough risk/benefit evaluation for individual patients. Considering the risk factors for the development of VTE and bleeding events in addition to recent study results may be helpful for correct initiation of primary pharmacological prevention and treatment of cancer-associated thrombosis(CAT), preferably with low molecular weight heparins(lMWH). Whereas thromboprophylaxis is most often recommended in hospitalized surgical and non-surgical patients with malignancy, there is less agreement as to its duration. With regard to ambulatory cancer patients, the lack of robust data results in low grade recommendations against routine use of anticoagulant drugs. Anticoagulation with lMWH for the first months is the evidence-based treatment for acute CAT, but duration of secondary prevention and the drug of choice are unclear. Based on published guidelines and literature, this review will focus on prevention and treatment strategies of VTE in patients with gastrointestinal cancers.

关键词： Thromboembolism Gastrointestinal cancer Prophylaxis Treatment Anticoagulation