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Model-based evaluation on the conversion ratio of ammonium to nitrite in a nitritation process for ammonium-rich wastewater treatment

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Journal of Environmental Sciences 2004年第6期16卷 1005-1010页

作者： LIXiao-ming YANGQi ZENGGuang-ming A.Cornelius K.h.Rosenwinkel S.Kunst D.Weichgrebe DepartmentofEnvironmentalScienceandEngineering HunanUniversityChangsha410082China InstituteofWaterQualityandWasteManagement HannoverUniversityWelfengartenD-130167HannoverGermany

Modeling for nitritation process was discussed and analyzed quantitatively for the factors that influence nitrite accumulation. The results indicated that ph, inorganic carbon source and hydraulic Retention Time(hRT) as well as biomass concentration are the main factors that influenced the conversion ratio of ammonium to nitrite. A constant high ph can lead to a high nitritation rate and results in high conversion ratio on condition that free ammonia inhibition do not happen. In a CSTR system, without ph control, this conversion ratio can be monitored by ph variation in the reactor. The ph goes down far from the inlet level means a strongly nitrite accumulation. high concentration of alkalinity can promoted the conversion ratio by means of accelerating the nitritation rate through providing sufficient inorganic carbon source(carbon dioxide). When inorganic carbon source was depleted, the nitritation process stopped. hRT adjustment could be an efficient way to make the nitritation system run more flexible, which to some extent can meet the requirements of the fluctuant of inlet parameters such as ammonium concentration, ph, and temperature and so on. Biomass concentration is the key point, especially for a CSTR system in steady state, which was normally circumscribed by the characteristics of bacteria and may also affected by aeration mode and can be increased by prolonging the hRT on the condition of no nitrate accumulation when no recirculation available. The higher the biomass concentration is, the better the nitrite accumulation can be obtained.

关键词： conversion ratio modeling analysis nitritation process nitrite accumulation

装配式建筑——复杂城市生态系统中的共识对象和联盟型城市主义

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世界建筑 2024年第1期 64-65页

作者：阿里尔·哈科维奇简·布罗迪孙斯坦(译) 阿里尔·哈科维奇建筑事务所不详

15年来,阿里尔·哈科维奇建筑事务所一直致力于装配式建筑,这是一种与组织合作开展建筑项目的研究实践。装配式建筑描述了一种全新的建筑制作方式,通过体系化的装配改善居住环境。“装配”这一概念是一种手段,它将建筑设计—生产实验室... 详细信息

15年来,阿里尔·哈科维奇建筑事务所一直致力于装配式建筑,这是一种与组织合作开展建筑项目的研究实践。装配式建筑描述了一种全新的建筑制作方式,通过体系化的装配改善居住环境。“装配”这一概念是一种手段,它将建筑设计—生产实验室与支撑和驱动这些设计的情景联系起来。这一过程所产生的不仅仅是设计提案,即构建或可视化潜在的转变,更是对替代生活方式和空间的预设。

关键词：装配式建筑建筑事务所建筑设计居住环境城市主义城市生态系统科维奇可视化

Benzene degradation in waste gas by photolysis and photolysis-ozonation： experiments and modeling

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Frontiers of Environmental Science & Engineering 2016年第6期10卷 103-112页

作者： Fariba Mahmoudkhani Maryam Rezaei Vahid Asili Mahsasadat Atyabi Elena Vaisman Cooper h. Langford Alex De Visscher Department of Chemical and Petroleum Engineering Centre for Environmental Engineering Research and Education (CEERE) Schulich School of Engineering University of Calgary 2500 University Drive NW Calgary Alberta T2N 1N4 Canada Department of Chemistry Faculty of Science University of Calgary 2500 University Drive NW Calgary Alberta T2N 1N4 Canada Present address: Institute for Resources Environment and Sustainability University of British Columbia 2202 Main Hall Vancourer BC V6T 1Z4 Canada

The degradation of benzene, a carcinogenic air pollutant, was studied in a gas-phase photochemical reactor with an amalgam lamp emitting ultraviolet light at 185 and 254 nm. Efficient benzene degradation （〉70%） was possible for benzene mass flow rates of up to 1.5 ***1. Adding ozone allowed benzene mass flow rates of up to 5 m ***-1 tobe treated with the same efficiency. In terms of energy consumption, ozone doubles the efficiency of the process. A comprenenslve mecnanisnc simulation model was developed incorporating a chemical kinetics model （62 reactions involving 47 chemical species）, a material balance model incorporating diffusion and flow, a flow velocity model,and a light field model. The model successfully predicted the efficiency of the reactor, generally within 20%, which indicates that the model is sound, and can be used for feasibility studies. The prediction of the reactor efficiency in the presence of ozone was less successful, with systematically overestimated efficiency. Condensation of reaction products in the reactor is thought to be the mare cause of model inaccuracy. Both experimental .data and model predictions show that there is a synergistic effect between ozonation and ultraviolet degradation.

关键词： Photolysis OzoneBenzene Waste gas Simulation Synergism

Thermomechanical Analysis of (Cu_(0.5)Tl_(0.5))-1223 Substituted by Pr and La

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作者： (美)G.h布朗

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Journal of Materials Science & Technology 2012年第2期28卷 169-176页

作者： A.I.Abou Aly R.Awad I.h.Ibrahim M.Kamal M.Anas Physics Department Faculty of ScienceAlexandria University Physics Department Faculty of ScienceMansoura University

The thermomechanical analysis （TMA） of Cu0.5T10.5Ba2Ca2-xRxCu30110-δ, where R=Pr and La, with 0.0〈x〈0.15, was carried out in temperature range from 450 to 1145 K. The samples were prepared by singlestep solid state reaction technique. The prepared samples were characterized by X-ray diffraction （XRD） and scanning electron microscopy （SEM）. The superconductivity of the prepared samples was investigated by electrical resistivity measurement. The results showed that low substitution content enhanced the （Cu0.5Tlo.5）- 1223 phase formation, while the higher substitution content degraded this phase. The higher superconducting transition temperatures Tc were found to be 114 K and 109 K at x= 0.025 for Pr- and La-substitutions, respectively. The average linear thermal expansion coefficient increased as x increased, while the shrinkage temperature decreased as x increased. Those results were emphasized by porosity and Vickers microhardness calculations. Debye temperature 0D was calculated from the linear thermal expansion coefficient data and correlated to Tc to estimate the electron-phonon coupling λep.

关键词： (Cu0.5Tl0.5)-1223 Thermomechanical analysis Thermal expansion coefficient Debye temperature

Effects of rotation and magnetic field on the nonlinear peristaltic flow of a second-order fluid in an asymmetric channel through a porous medium

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Chinese Physics B 2013年第7期22卷 303-313页

作者： A. M. Abd-Alla S. M. Abo-Dahab h. D. El-Shahrany Department of Mathematics Faculty of ScienceTaif University Department of Mathematics Faculty of Science Department of Mathematics Faculty of ScienceSouth Valley University

In this paper, the effects of both rotation and magnetic field of the peristaltic transport of a second-order fluid through a porous medium in a channel are studied analytically and computed numerically. The material is represented by the constitutive equations for a second-order fluid. Closed-form solutions under the consideration of long wavelength and low Reynolds number is presented. The analytical expressions for the pressure gradient, pressure rise, friction force, stream function, shear stress, and velocity are obtained in the physical domain. The effects of the non-dimensional wave amplitude, porosity, magnetic field, rotation, and the dimensionless time-mean flow in the wave frame are analyzed theoretically and computed numerically. Numerical results are given and illustrated graphically in each case considered. Comparison was made with the results obtained in the presence and absence of rotation, magnetic field, and porosity. The results indicate that the effects of the non-dimensional wave amplitude, porosity, magnetic field, rotation, and the dimensionless time-mean flow are very pronounced in the phenomena.

关键词： peristaltic flow second-order fluid magnetic field porous medium

Robust cost efficacy of a novel,validated screening test at 12–20 Weeks gestation for the prediction of preterm birth(PTB)at or before 32 Weeks in singletons

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Gynecology and Obstetrics Clinical Medicine 2021年第3期1卷 107-111页

作者： Robert h.Lee Carl P.Weiner Departments of Population health University of Kansas School of MedicineUSA Departments of Obstetrics and Gynecology and Molecular and Integrative Physiology University of Kansas School of MedicineKansas CityKS66160USA

Objective:Preterm birth(PTB)at or before 32 weeks complicates up to 2%of United States(US)births and accounts for 80%of perinatal expenditures in the first year of *** screening tests for PTB performed from 12 weeks to 19 weeks 5 days have receiver operated area under the curve(AUC)indices ofh™,a unique maternal screening test comprised of plasma cell-free RNA for the prediction of PTB≦32 weeks due to spontaneous labor(sPTB)with or without preterm premature rupture of the membranes(PPROM)or early-onset pre-eclampsia before 34 weeks(EOP).FutureBIRTh™is supported by multiple validation studies derived from 12 weeks to 19 weeks 5 days gestation achieving AUCs of 84.2%for sPTB and 94.1%for ***:Using the US rates for EOP(0.5%)and sPTB≦32 weeks(1.8%)and adjusting the US pregnancy/neonatal medical costs to US dollars(2017 value),we calculated the cost per 100,000 singletons with or without universal FutureBIRTh™testing before 19 weeks and 6 days using three detection rates and assuming screenpositive women would be treated with and respond to aspirin(assumed 80%efficacy for EOP)and vaginal progesterone(assumed 38%efficacy for sPTB).We also assessed test performance at disease incidence rates below that of the US(down to 0.46%).For considering screening costs,we assumed test costs of$750,and treatment costs of$1000 for patients over 20 weeks gestational ***:The identification and treatment of‘at-risk’pregnancies by FutureBIRTh™with existing therapies would reduce direct healthcare costs by up to$95 million per 100,000 *** projected savings were robust and achievable at each FutureBIRTh™price despite the conservative costs,efficacy,and detection rate *** incidence of PTB≦32 weeks would decline by 40%–50%with a test cost of$750 and an 80%detection ***:The accurate risk assessment provided by universal FutureBIRTh™screening coupled with existing preventative treatments could lea

关键词： Pregnancy Preterm birth Transcriptome Plasma RNA Precision medicine

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美国语文

作者： (美)威廉·h·麦加菲

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