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Application of a water quality model for determining instream aeration station location and operational rules:A case study

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Water science and Engineering 2018年第1期11卷 8-16页

作者： charles s.Melching Melching Water solutions LLC GreenfieldWI 53221USA

Instream aeration has been used as a supplement to secondary treatment or a substitute for tertiary treatment for meeting dissolved oxygen （DO） standards in rivers. Many studies have used water quality models to determine the number, location, and capacity of instream aeration stations （IAss） needed to meet DO standards in combination with other pollution control measures. DO concentrations have been improved in the North shore Channel and North Branch Chicago River by the Devon Avenue IAs for more than 35 years. A study was initiated to determine whether it was better to rehabilitate or relocate this station and to determine appropriate operational guidance for the IAs at the selected location. A water quality model capable of simulating DO concentrations during unsteady flow was used to evaluate the proper location for an IAs and operational guidance for this IAs. Three test years, a dry year, a wet year, and an extreme year, were considered in the evaluation. The study found that the Devon Avenue IAs should be rehabilitated as this location performed as well as or better than any of 10 alternative locations. According to the new operational guidance for this IAs, the amount of time with blowers operating could be substantially reduced compared to traditional operations while at the same time the attainment of the DO standards could be increased. This study shows that a carefully designed modeling study is key to effective selection, location, and operation of IAss such that attainment of DO standards can be maximized while operation hours of blowers can be minimized.

关键词： Instream aeration Dissolved oxygen Water quality modeling Water quality management Computer simulation

Numerical modelling of reinforced concrete flexural members strengthened using textile reinforced mortars

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Frontiers of structural and Civil Engineering 2023年第4期17卷 649-668页

作者： Naveen Revanna charles K.s.Moy Department of Civil Engineering Xi’an Jiaotong-Liverpool UniversitySuzhou 215123China

Externally bonded(EB)and near-surface mounted(NsM)bonding are two widely adopted and researched strengthening methods for reinforced-concrete *** composite substrates are easy to reach and repair using appropriate surface treatments,whereas NsM techniques can be easily applied to the soffit and concrete member *** EB bonded fiber-reinforced polymer(FRP)technique has a significant drawback:combustibility,which calls for external protective agents,and textile reinforced mortar(TRM),a class of EB composites that is noncombustible and provides a similar functionality to any EB FRP-strengthened *** study employs a finite element analysis technique to investigate the failing failure of carbon textile reinforced mortar(CTRM)-strengthened reinforced concrete *** principal objective of this numerical study was to develop a finite element model and validate a set of experimental data in existing literature.A set of seven beams was modelled and calibrated to obtain concrete damage plasticity(CDP)*** predicted results,which were in the form of load versus deflection,load versus rebar strain,tensile damage,and compressive damage patterns,were in good agreement with the experimental ***,a parametric study was conducted to verify the applicability of the numerical model and study various influencing factors such as the concrete strength,internal reinforcement,textile roving spacing,and externally-applied load *** ultimate load and deflection of the predicted finite element results had a coefficient of variation(COV)of 6.02%and 5.7%,respectively.A strain-based numerical comparison with known methods was then conducted to investigate the debonding *** developed finite element model can be applied and tailored further to explore similar TRM-strengthened beams undergoing debonding,and the preventive measures can be sought to avoid premature debonding.

关键词： fiber reinforced polymer textile reinforced mortar finite element analysis concrete damage plasticity calibration and validation parametric study

Uniform Asymptotic Expansion of the Voltage Potential in the Presence of Thin Inhomogeneities with Arbitrary Conductivity

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Chinese Annals of Mathematics,series B 2017年第1期38卷 293-344页

作者： charles DAPOGNY Michael s.VOGELIUs Laboratoire Jean Kuntzmann CNRSUniversité Grenoble-Alpes Department of Mathematics Rutgers University

Asymptotic expansions of the voltage potential in terms of the "radius" of a diametrically small(or several diametrically small) material inhomogeneity(ies) are by now quite well-known. such asymptotic expansions for diametrically small inhomogeneities are uniform with respect to the conductivity of the *** contrast, thin inhomogeneities, whose limit set is a smooth, codimension 1 manifold,σ, are examples of inhomogeneities for which the convergence to the background potential,or the standard expansion cannot be valid uniformly with respect to the conductivity, a, of the inhomogeneity. Indeed, by taking a close to 0 or to infinity, one obtains either a nearly homogeneous Neumann condition or nearly constant Dirichlet condition at the boundary of the inhomogeneity, and this difference in boundary condition is retained in the *** purpose of this paper is to find a "simple" replacement for the background potential, with the following properties:(1) This replacement may be(simply) calculated from the limiting domain Ω\σ, the boundary data on the boundary of Ω, and the right-hand side.(2) This replacement depends on the thickness of the inhomogeneity and the conductivity,a, through its boundary conditions on σ.(3) The difference between this replacement and the true voltage potential converges to 0 uniformly in a, as the inhomogeneity thickness tends to 0.

关键词： Uniform asymptotic expansions Conductivity problem Thin inhomogeneities

A comprehensive investigation on nonlinear vibration and bending characteristics of bio-inspired helicoidal laminated composite structures

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Applied Mathematics and Mechanics(English Edition) 2025年第1期46卷 81-100页

作者： s.sAURABH R.KIRAN D.sINGH R.VAIsH V.s.CHAUHAN school of Mechanical and Materials Engineering Indian Institute of Technology Mandi

Bio-inspired helicoidal composite laminates, inspired by the intricate helical structures found in nature, present a promising frontier for enhancing the mechanical properties of structural designs. Hence, this study provides a comprehensive investigation into the nonlinear free vibration and nonlinear bending behavior of bio-inspired composite plates. The inverse hyperbolic shear deformation theory(IHsDT) of plates is employed to characterize the displacement field, with the incorporation of Green-Lagrange nonlinearity. The problem is modeled using the C0finite element method(FEM), and an in-house code is developed in the MATLAB environment to solve it numerically. Various helicoidal layup configurations including helicoidal recursive(HR), helicoidal exponential(HE), helicoidal semi-circular(Hs), linear helicoidal(lh), and Fibonacci helicoidal(FH)with different layup sequences and quasi-isotropic configurations are studied. The model is validated, and parametric studies are conducted. These studies investigate the effects of layup configurations, side-to-thickness ratio, modulus ratios, boundary conditions, and loading conditions at different load amplitudes on the nonlinear vibration and nonlinear bending behaviors of bio-inspired composite plates. The results show that the laminate sequence exerts a substantial impact on both nonlinear natural frequencies and nonlinear bending behaviors. Moreover, this influence varies across different side-to-thickness ratios and boundary conditions of the bio-inspired composite plate.

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Experimental evaluation of the effect of storm movement on peak discharge

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International Journal of sediment Research 2015年第2期30卷 167-177页

作者： Jin Liang charles s.Melching Department of Civil Construction and Environmental EngineeringMarquette University

The hypothesis that downstream moving storms with storm length less than watershed length（L;/L< 1.0） magnify the peak discharges as indicated by kinematic-wave models in previous studies was evaluated in an analysis... 详细信息

The hypothesis that downstream moving storms with storm length less than watershed length（L;/Lscharges as indicated by kinematic-wave models in previous studies was evaluated in an analysis of the dimensionless peak discharge and dimensionless storm *** unpublished experimental data collected for a V-shaped watershed in the Watershed Experimentation system（WEs） at the University of Illinois at Urbana-Champaign,were used in comparison with the simulation results of a kinematic-wave *** is found that downstream moving storms with L;/L se the peak discharges to a limited extent compared to stationary storms,and the kinematic-wave model overstates the increase in the peak flows resulting from downstream moving storms with L;/L s in the experimental watershed,the accuracy of kinematic-wave and dynamic-wave models for the simulation of surface runoff resulting from upstream and downstream moving storms was evaluated utilizing the same experimental *** kinematic-wave model simulates the upstream moving storms pretty well,***-sutcliffe coefficient of model fit efficiency equal to 0.948 and 0.831 for storms lengths equal to and not equal to the watershed length,***,the kinematic wave model substantially overestimates the peak discharge of downstream moving storms,and yields generally poorer fits than for upstream moving storm,*** equal to 0.867 and 0.674 for storms with lengths equal to and not equal to the watershed length,*** dynamic-wave model simulates the downstream moving storms pretty well,*** equal to 0.843 and 0.879 for storms with lengths equal to and not equal to the watershed length,respectively,indicating backwater significantly affects runoff for even this simple experimental *** that storm movement did not substantially magnify peak discharge,the assumption of stationary storms made

关键词： Moving storms Kinematic-wave Dynamic-wave Experimental data Dimensional analysis

Afforestation,restoration and regeneration——Not all trees are created equal

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Journal of Forestry Research 2014年第1期25卷 3-20页

作者： shaneka s.Lawson charles H.Michler UsDA Forest service Northern Research StationHardwood Tree Improvement and Regeneration Center (HTIRC)Purdue UniversityDepartment of Forestry and Natural Resources

Undulations in weather patterns have caused climate shifts of increased frequency and duration around the world. The need for additional research and model data on this pressing problem has resulted in a plethora of research groups examining a particular tree species or biome for negative effects of climate change. This review aims to （1） collect and merge recent research data on regeneration within old- and new-growth forests, （2） highlight and expand upon selected topics for additional discussion, and （3） report how shade tolerance, drought toler- ance, and inherent plasticity affect tree growth and development. Al- though shade and drought tolerance have been well studied by a number of research groups, this review reveals that in-depth analysis of a single or a few species in a given area will not generate the data required to implement a successful regeneration plan. studies using historical accounts of previous species composition, information regarding site sea- sonality, species competition, and individual responses to drought and shade are needed to （1） develop best management plans and （2） ensure future modeling experiments are focused on a greater variety of species using more innovative methods to evaluate climate change effects.

关键词： Climate change shade tolerance drought tolerance canopy gaps invasive species

Kinematic analysis of penile reflexes in a rat model of spinal cord injury

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Asian Journal of Andrology 2021年第1期23卷 30-35页

作者： Casey J steadman sai s Vangoor charles H Hubscher Department of Anatomical sciences and Neurobiology University of LouisvilleLouisvilleKY 40202USA Kentucky spinal Cord Injury Research Center LouisvilleKY 40202USA.

The ex-copula penile dorsiflexion reflex(PDFR)is an established measure of sexual dysfunction in male rat models of spinal cord *** the PDFR after complete spinal transection is well described,information regarding the more clinically relevant incomplete spinal contusion injury model is *** study examined,using two-dimensional(2D)kinematic analysis,the relationship between the PDFR and degree of white matter sparing(WMs).Male Wistar rats received a T9 contusion with varying degrees of impactor *** kinematic recordings of the PDFR were made 3-8 weeks *** reflex components examined included maximum angle of penile dorsiflexion,total penile event duration,and penile ascent *** hoc comparison between animals grouped based upon injury severity(moderate-severe:13.33%-17.15%WMs vs moderate:20.85%-33.50%WMs)ndicated PDFR ***,the numbers of animals with more moderate contusions having data points above the median n both maximum angle of penile dorsiflexion and penile ascent speed were significantly lower than animals with more severe *** penile event duration was also affected but only at more chronic time points(6-8 weeks).Thus,2D kinematic analysis of the PDFR allows for more consistent and quantifiable analysis of the subtle differences that can occur between injury severity groups in the rat contusion model.

关键词： erection penile sexual dysfunction spinal cord injury

Flavonoids:New Roles for Old Molecules

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Journal of Integrative Plant Biology 2010年第1期52卷 98-111页

作者： charles s. Buer Nijat Imin Michael A. Djordjevic Genomic Interactions Group ARC Centre of Excellence for Integrative Legume Research Research School of Biology College of Medicine Biology and Environment The Australian National University

Flavonoids are ubiquitous in the plant kingdom and have many diverse functions including defense, UV protection, auxin transport inhibition, allelopathy, and flower coloring. Interestingly, these compounds also have considerable biological activity in plant, animal and bacterial systems - such broad activity is accomplished by few compounds. Yet, for all the research over the last three decades, many of the cellular targets of these secondary metabolites are unknown. The many mutants available in model plant species such as Arabidopsis thaliana and Medicago truncatula are enabling the intricacies of the physiology of these compounds to be deduced. In the present review, we cover recent advances in flavonoid research, discuss deficiencies in our understanding of the physiological processes, and suggest approaches to identify the cellular targets of flavonoids.

关键词： Flavonoids DPBA Figure TTG root

Operational guidance for aeration and flow augmentation for the Chicago Area Waterway system—A case study

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Water science and Engineering 2023年第4期16卷 345-358页

作者： charles s.Melching Jennifer Wasik Ed staudacher Thomas Minarik Melching Water solutions LLC GreenfieldWI 53221USA Metropolitan Water Reclamation District of Greater Chicago ChicagoIL 60611USA Metropolitan Water Reclamation District of Greater Chicago CiceroIL 60804USA

The Chicago Area Waterway system(CAWs)is a 133.9 km branching network of navigable waterways controlled by hydraulic structures,in which the majority of the flow is treated wastewater effluent and there are periods of substantial combined sewer *** CAWs comprises a network of effluent dominated *** stringent dissolved oxygen(DO)standards and a reduced flow augmentation allowance have been recently applied to the ***,a carefully calibrated and verified one-dimensional flow and water quality model was applied to the CAWs to determine emission-based real-time control guidelines for the operation of flow augmentation and aeration *** goal of these guidelines was to attain DO standards at least 95%of the ***“optimal”guidelines were tested for representative normal,dry,and wet *** finally proposed guidelines were found in the simulations to attain the 95%target for nearly all locations in the CAWs for the three test *** developed operational guidelines have been applied since 2018 and have shown improved attainment of the DO standards throughout the CAWs while at the same time achieving similar energy use at the aeration stations on the Calumet River system,greatly lowered energy use on the Chicago River system,and greatly lowered discretionary diversion from Lake Michigan,meeting the recently enacted lower amount of allowed annual discretionary *** case study indicates that emission-based real-time control developed from a well calibrated model holds potential to help many receiving water bodies achieve high attainment of water quality standards.

关键词： Water quality modeling Water quality management Real-time control stream aeration Flow augmentation Dissolved oxygen