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Influence of MBBR carrier geometrical properties and biofilm thickness restraint on biofilm properties,effluent particle size distribution,settling velocity distribution,and settling behaviour

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Journal of Environmental Sciences 2022年第12期34卷 138-149页

作者： Raheleh Arabgol Peter A.Vanrolleghem robert delatolla Department of Civil Engineering University of Ottawa161 Louis PasteurK1N 6N5 ONCanada ModelEAU Département de génie civil et de génie des eauxUniversitéLaval1065 av.de la MédecineQuébecCanada

The relatively poor settling characteristics of particles produced in moving bed biofilm reactor(MBBR)outline the importance of developing a fundamental understanding of the characterization and settleability of MBBR-produced *** influence of carrier geometric properties and different levels of biofilm thickness on biofilm characteristics,solids production,particle size distribution(PSD),and particle settling velocity distribution(PSVD)is evaluated in this *** analytical Vi CAs method is applied to the MBBR effluent to assess the distribution of particle settling *** method is combined with microscopy imaging to relate particle size distribution to settling *** conventionally loaded MBBR systems are studied at a similar loading rate of 6.0 g/(m^(2)·day)and with different carrier *** AnoxK^(TM)K5 carrier,a commonly used carrier,is compared to so-called thickness-restraint carriers,AnoxK^(TM)Z-carriers that are newly designed carriers to limit the biofilm ***,two levels of biofilm thickness,200μm and 400μm,are studied using AnoxK^(TM)Z-200 and Z-400 *** analysis confirms that K5 carriers demonstrated a significantly different biofilm mass,thickness,and density,in addition to distinct trends in PSD and PSVD in comparison with ***,in comparison of thickness-restraint carriers,Z-200 carrier results did not vary significantly compared to the Z-400 *** K5 carriers showed the lowest production of suspended solids(0.7±0.3 gTSS/day),thickest biofilm(281.1±8.7μm)and lowest biofilm density(65.0±1.5 kg/m^(3)).The K5 effluent solids also showed enhanced settling behaviour,consisting of larger particles with faster settling velocities.

关键词： MBBR Particle size distribution(PSD) Particle settling velocity distribution(PSVD) Settling behaviour ViCAs z-carriers

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An exploration of the relationship between wastewater viral signals and COVID-19 hospitalizations in Ottawa,Canada

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Infectious Disease Modelling 2023年第3期8卷 617-631页

作者： K.Ken Peng Elizabeth M.Renouf Charmaine B.Dean X.Joan Hu robert delatolla Douglas G.Manuel Department of Statistics and Actuarial Science Simon Fraser University8888 University DrBurnabyV5A 1S6BCCanada Department of Statistics and Actuarial Science University of Waterloo200 University Ave WWaterlooN2L 3G1ONCanada Department of Civil Engineering University of Ottawa75 Laurier Ave.EOttawaK1N 6N5ONCanada The Ottawa Hospital Research Institute 1053 Carling AveOttawaK1Y 4E9ONCanada Department of Family Medicine University of Ottawa75 Laurier Ave.EOttawaK1N 6N5ONCanada School of Epidemiology and Public Health University of Ottawa75 Laurier Ave.EOttawaK1N 6N5ONCanada

Monitoring of viral signal in wastewater is considered a useful tool for monitoring the burden of COVID-19,especially during times of limited availability in *** have shown that COVID-19 hospitalizations are highly correlated with wastewater viral signals and the increases in wastewater viral signals can provide an early warning for increasing hospital *** association is likely nonlinear and *** project employs a distributed lag nonlinear model(DLNM)(Gasparrini et al.,2010)to study the nonlinear exposure-response delayed association of the COVID-19 hospitalizations and SARS-CoV-2 wastewater viral signals using relevant data from Ottawa,*** consider up to a 15-day time lag from the average of SARS-CoV N1 and N2 gene concen-trations to COVID-19 *** expected reduction in hospitalization is adjusted for vaccination efforts.A correlation analysis of the data verifies that COVID-19 hospital-izations are highly correlated with wastewater viral signals with a time-varying *** DLNM based analysis yields a reasonable estimate of COVID-19 hospitalizations and enhances our understanding of the association of COVID-19 hospi-talizations with wastewater viral signals.

关键词： Wastewater surveillance COVID-19 vaccination effectiveness Distributed lag nonlinear model Time varying correlation

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Natural continuous influent nitrifier immigration effects on nitrification and the microbial community of activated sludge systems

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Journal of Environmental Sciences 2018年第12期30卷 159-167页

作者： Lifang Yu Ren Li robert delatolla Ru Zhang Xiuling Yang Dangcong Peng School of Environmental and Municipal Engineering Xi'an University of Architecture and Technology Department of Civil Engineering University of Ottawa

Two sequencing batch reactors（SBRs） were operated for 100 days under aerobic conditions,with one being fed with unsterilized municipal wastewater（USBR）, and the other fed with sterilized municipal wastewater（SSBR）. Respirometric assays and fluorescence in situ hybridization（FISH） results show that active nitrifiers were present in the unsterilized influent municipal wastewater. The maximum ammonia utilization rate（AUR） and nitrite utilization rate（NUR） of the unsterilized influent were 0.32 ± 0.12 mg NH4＋-N/（L·hr） and0.71 ± 0.18 mg NO2--N/（L·hr）. Based on the maximum utilization rates, the estimated seeding intensity for the ammonia oxidizing bacteria（AOB） and nitrite oxidizing bacteria（NOB） of the USBR was 0.08 g AOB/（g AOB·day） and 0.20 g NOB/（g NOB·day） respectively. The fraction of nitrifiers/total bacteria in the influent was 5.35% ± 2.1%, the dominant AOB was Nitrosomonas spp., Nitrosococcus mobilis hybridizated with Nsm156, and the dominant NOB was Nitrospira hybridizated with Ntspa662. The influent nitrifiers potentially seeded the activated sludge of the bioreactor and hence demonstrated a mitigation of the acclimatization times and instability during start-up and early operation. The AUR and NUR in the USBR was 15% and 13% higher than the SSBR respectively during the stable stage, FISH results showed that nitrifiers population especially the Nitrospira in the USBR was higher than that in the SSBR. These results indicate that the natural continuous immigration of nitrifiers from municipal influent streams may have some repercussions on the modeling and design of bioreactors.

关键词： Nitrifier immigration Influent wastewater Seeding effect Nitrification Nitrospira

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Predicting the coefficient of friction in a sliding contact by applying machine learning to acoustic emission data

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Friction 2024年第6期12卷 1299-1321页

作者： robert GUTIERREZ Tianshi FANG robert MAINWARING Tom REDDYHOFF Tribology Group Department of Mechanical EngineeringImperial College LondonExhibition RoadLondon SW72AZUK Shell Global Solutions(US)Inc.Shell Technology Center Houston 3333 Highway 6 SouthHoustonTX 77082USA Shell International Petroleum Company Limited Shell CentreYork RoadLondon SE17NAUK

It is increasingly important to monitor sliding interfaces within machines,since this is where both energy is lost,and failures *** emission(AE)techniques offer a way to monitor contacts remotely without requiring transparent or electrically conductive ***,acoustic data from sliding contacts is notoriously complex and difficult to ***,we simultaneously measure coefficient of friction(with a conventional force transducer)and acoustic emission(with a piezoelectric sensor and high acquisition rate digitizer)produced by a steel‒steel rubbing *** data is then used to train machine learning(ML)algorithms(e.g.,Gaussian process regression(GPR)and support vector machine(SVM))to correlated acoustic emission with *** training requires the dense AE data to first be reduced in size and a range of processing techniques are assessed for this(e.g.,down-sampling,averaging,fast Fourier transforms(FFTs),histograms).Next,fresh,unseen AE data is given to the trained model and the resulting friction predictions are compared with the directly measured *** is excellent agreement between the measured and predicted friction when the GPR model is used on AE histogram data,with root mean square(RMS)errors as low as 0.03 and Pearson correlation coefficients reaching ***,predictions remain accurate despite changes in test conditions such as normal load,reciprocating frequency,and stroke *** paves the way for remote,acoustic measurements of friction in inaccessible locations within machinery to increase mechanical efficiency and avoid costly failure/needless maintenance.

关键词： acoustic emission condition monitoring friction machine learning Gaussian process regression support vector machine

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Comparison of approaches to quantify SARS-CoV-2 in wastewater using RT-qPCR: Results and implications from a collaborative inter-laboratory study in Canada

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Journal of Environmental Sciences 2021年第9期33卷 218-229页

作者： Alex H.S.Chik Melissa B.Glier Mark Servos Chand S.Mangat Xiao-Li Pang Yuanyuan Qiu Patrick M.D’Aoust Jean-Baptiste Burnet robert delatolla Sarah Dorner Qiudi Geng John P.Giesy Jr robert Mike McKay Michael R.Mulvey Natalie Prystajecky Nivetha Srikanthan Yuwei Xie Bernadette Conant Steve E.Hrudey Canadian SARS-CoV-Inter-Laboratory Consortium Consultant to Canadian Water Network Inc. KitchenerCanada Presently at Ontario Clean Water Agency MississaugaCanada Environmental Microbiology BC Centre for Disease ControlVancouverCanada Department of Biology University of WaterlooWaterlooCanada National Microbiology Laboratory Public Health Agency of CanadaWinnipegCanada Public Health Laboratory Alberta Precision LaboratoryEdmontonCanada Department of Laboratory Medicine&Pathology Faculty of Medicine and DentistryUniversity of AlbertaEdmontonAB T6G 2G3Canada Faculty of Engineering University of OttawaOttawaCanada Département des génies civil géologique et des minesPolytechnique MontréalMontréalCanada Veterinary Biomedical Sciences University of SaskatchewanSaskatoonCanada Toxicology Centre University of SaskatchewanSaskatoonCanada Great Lakes Institute for Environmental Research University of WindsorWindsorCanada Department of Medical Microbiology University of ManitobaWinnipegCanada Department of Pathology and Laboratory Medicine University of British ColumbiaVancouverCanada Canadian Water Network Inc. WaterlooCanada Group author details below

Detection of SARS-CoV-2 RNA in wastewater is a promising tool for informing public health decisions during the COVID-19 ***,approaches for its analysis by use of reverse transcription quantitative polymerase chain reaction(RT-q PCR)are still far from standardized *** characterize inter-and intra-laboratory variability among results when using various methods deployed across Canada,aliquots from a real wastewater sample were spiked with surrogates of SARS-CoV-2(gamma-radiation inactivated SARS-CoV-2 and human coronavirus strain 229E[HCoV-229E])at low and high levels then provided"blind"to eight *** estimates reported by individual laboratories were consistently within a 1.0-log_(10) range for aliquots of the same spiked *** laboratories distinguished between low-and high-spikes for both *** expected,greater variability was observed in the results amongst laboratories than within individual laboratories,but SARS-CoV-2 RNA concentration estimates for each spiked condition remained mostly within 1.0-log_(10) *** no-spike wastewater aliquots provided yielded non-detects or trace levels(<20 gene copies/mL)of SARS-CoV-2 *** appear linked to methods that included or focused on the solids fraction of the wastewater matrix and might represent in-situ SARS-CoV-2 to the wastewater ***-229E RNA was not detected in the no-spike ***,all methods yielded comparable results at the conditions *** behavior of SARS-CoV-2 and spiked surrogates in wastewater should be considered to evaluate method effectiveness.A consistent method and laboratory to explore wastewater SARS-CoV-2 temporal trends for a given system,with appropriate quality control protocols and documented in adequate detail should succeed.

关键词： COVID-19 Wastewater surveillance Public health Quality assurance Quality control

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Necrotic enteritis and antibiotic-free production of broiler chickens:Challenges in testing and using alternative products

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Animal Nutrition 2024年第1期16卷 288-298页

作者： robert J.Moore School of Science RMIT University

The global trend towards raising broiler chickens without the use of in-feed antibiotics(IFAs) means that there is an ongoing need to develop alternative treatments capable of delivering the benefits that IFAs previously provided. IFAs supported the productivity performance of chickens and played a key role in maintaining their health. Necrotic enteritis(NE) is an important disease of broilers that affects health,productivity, and welfare, and was previously well controlled by IFAs. However, with the reduction in IFA use, NE is resurgent in some countries. Vaccines and various feed additives, including pre-, pro-, and postbiotics, phytobiotics, fatty acids, and phage therapies have been introduced as alternative methods of NE control. While some of these feed additives have specific activity against the NE pathogen, Clostridium perfringens, most have the more general goal of reinforcing gut health. Extensive reviews of the effects of many of these feed additives on gut health have been published recently. Hence, rather than cover previously well reviewed areas of research this review focuses on the challenges and pitfalls in undertaking experimental assessment of alternative NE treatments and translating laboratory research to real world commercial production settings. The review is based on the author's particular experience,reading, thoughts, and analysis of the available information and inevitably presents a particular understanding that is likely to be at odds with others thinking on these issues. It is put forward to stimulate thinking and discussion on the issues covered.

关键词： Necrotic enteritis Clostridium perfringens Vaccines Feed additive Farm management

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A detailed rock density model of the Hong Kong territories

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Geodesy and Geodynamics 2024年第1期15卷 75-81页

作者： Albertini Nsiah Ababio robert Tenzer Department of Land Surveying and Geo-Informatics Hong Kong Polytechnic UniversityHong KongChina

We used the geological map and published rock density measurements to compile the digital rock density model for the Hong Kong *** then estimated the average density for the whole *** to our result,the rock density values in Hong Kong vary from 2101 to 2681 kg·m^(-3).These density values are typically smaller than the average density of 2670 kg·m^(-3),often adopted to represent the average density of the upper continental crust in physical geodesy and gravimetric geophysics *** finding reflects that the geological configuration in Hong Kong is mainly formed by light volcanic formations and lava flows with overlying sedimentary deposits at many locations,while the percentage of heavier metamorphic rocks is very low(less than 1%).This product will improve the accuracy of a detailed geoid model and orthometric heights.

关键词： Density model Rock types Gravimetric modeling Hong Kong

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Optimization of product characteristics of porous carbon agglomerates using a design of experiments in fluidized bed agglomeration

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Particuology 2024年第6期89卷 258-269页

作者： Martin Oelofse robert Rack Marcelle Hilden Peter Langguth Department of Pharmaceutical Technology and Biopharmaceutics Johannes Gutenberg UniversityMainzGermany Carbon Advanced Solutions GmbH HeuchelheimGermany

Spraying parameters during particle agglomeration processes can affect the agglomeration kinetics and particle *** study was conducted to better understand the influence of the spraying parameters in a fluidized bed wet agglomeration process,and the influence on the stability characteristics of carbon tablets.A formulation based on fine carbon and peroxide powder,as well as carboxymethyl cellulose as a binder,was used to produce agglomerates in a first production *** in a second production step carbon tablets with a high porosity were molded for the customer goods *** optimization of the compressive strength of these carbon tablets was the goal of the *** agglomerates were produced with a laboratory scale granulator called“ProCell”and were compressed with a five-cavity mechanical *** screening of the agglomeration process parameters and their influence on the agglomerates quality,as well as the performance characteristics of the carbon tablets,were investigated using a multilevel factorial *** experimental runs were done by varying atomized air pressure and feed rate of the *** was determined by the design *** findings of the statistical trials showed that low atomized air pressure and a low feed rate lead to a higher tablet compressive strength.

关键词： Wet agglomeration Fluidized bed Design of experiments Carbon agglomerates and tablets

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The influence of various grease compositions and silver nanoparticle additives on electrically induced rolling-element bearing damage

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Friction 2024年第4期12卷 796-811页

作者： Samuel BOND robert L.JACKSON German MILLS Department of Chemistry and Biochemistry Auburn UniversityAuburn 36849-5412USA Department of Mechanical Engineering Auburn UniversityAuburn 36849-5412USA

Leakage currents accelerate surface degradation of metal contacts via small scale arcing across lubricating films,but recent observations suggest that metallic nanoparticle additives in lubricants may be useful to improve contact *** findings prompted a study that examined electrically induced surface pitting of steel contacts in the presence of several lubricating greases including some containing nanometer-sized colloidal silver(Ag)*** rolling sphere-on-disk experiments were conducted under electro-tribological loads employing polyurea greases derived from mineral and synthetic base oils with and without *** forces and electrical resistance were monitored continuously during the tests;surface changes were characterized by means of optical spectroscopy,stylus profilometry,and scanning electron microscopy(SEM)including compositional analysis using energy dispersive spectroscopy(EDS).The observations demonstrate that surface pitting induced by arcing occurs mainly at the points were the rolling motion changes direction and that eroded metal is deposited along the wear ***-sized pits are formed which contain carbon and oxygen indicating that arcing causes decomposition of the hydrocarbon *** findings indicate a significant inhibition of pitting is induced by the Ag nanoparticles;some greases containing other additives exhibit a similar,although less pronounced,effect.

关键词： electric motor bearings wheel bearings electric vehicles arcing electrically induced bearing damage pitting leakage current stray current

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Potential of contemporary earth-sheltered buildings to achieve Plus Energy status in various European climates during the heating season

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Building Simulation 2024年第1期17卷 41-52页

作者： Aleksandar Nesovic Nebojsa Jurisevic robert Kowalik lvana Terzic Faculty of Engineering University of KragujevacSestre Janjic 634000 KragujevacSerbia Faculty of Environmental Geomatic and Energy EngineeringKielce University of TechnologyTysigclecia Panstwa Polskiego725-314 KielcePoland

This study investigates the potential of contemporary Earth-Sheltered Buildings to contribute to sustainable societies by achieving Plus Energy Building status during the heating *** buildings analyzed are intended to house a four-member family(102.5 m^(2)).The house is equipped with a ground source heat pump,geothermal vertical probes,floor heating panels,an energy recovery ventilator,and building-integrated photovoltaic panels installed on the exposed building *** numerical analysis(using EnergyPlus software)was carried out for nine European sites covering five different climatic zones(namely:southern,Atlantic,continental,alpine,and northern climate)and three latitude belts spanning Europe from south to *** above 65°N(northern and alpine climate)could not achieve Plus Energy status with 20% efficient *** 15% efficient BIPVs,the building above 59°N(northern climate)was incapable of achieving this as *** the monthly time step,the buildings in the southern and Atlantic climates with 15% efficient BiPVs were able to produce an energy surplus every month,as was the building in theAlps with 20% efficientBIPVs.

关键词： civil engineering earth-sheltered buildings renewable energy sustainable societies Plus Energy Buildings Energy Plus software

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