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Biological nutrient removal by internal circulation upflow sludge blanket reactor after landfill leachate pretreatment

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Journal of Environmental Sciences 2013年第10期25卷 2130-2137页

作者： Alkhafaji r.Abood Jianguo Bao Zaidun n.Abudi State Key Laboratory of Biogeology and Environmental Geology China University of Geosciences Thi Qar University Al-Mustansiryiah University College of Engineering

The removal of biological nutrient from mature landfill leachate with a high nitrogen load by an internal circulation upflow sludge blanket （ICUSB） reactor was studied. The reactor is a set of anaerobic-anoxic-aerobic （A^2/O） bioreactors, developed on the basis of an expended granular sludge blanket （EGSB）, granular sequencing batch reactor （GSBr） and intermittent cycle extended aeration system （ICEAS）. Leachate was subjected to stripping by agitation process and poly ferric sulfate coagulation as a pretreatment process, in order to reduce both ammonia toxicity to microorganisms and the organic contents. The reactor was operated under three different operating systems, consisting of recycling sludge with air （A^2/O）, recycling sludge without air （low oxygen） and a combination of both （A^2/O and low oxygen）. The lowest effluent nutrient levels were realised by the combined system of A^2/O and low oxygen, which resulted in effluent of chemical oxygen demand （COD）, nH3-n and biological oxygen demand （BOD5） concentrations of 98.20, 13.50 and 22.50 mg/L. The optimal operating conditions for the efficient removal of biological nutrient using the ICUSB reactor were examined to evaluate the influence of the parameters on its performance. The results showed that average removal efflciencies of COD and nH3- n of 96.49% and 99.39%, respectively were achieved under the condition of a hydraulic retention time of 12 hr, including 4 hr of pumping air into the reactor, with dissolved oxygen at an rate of 4 mg/L and an upflow velocity 2 m/hr. These combined processes were successfully employed and effectively decreased pollutant loading.

关键词： landfill leachate anaerobic-anoxic-aerobic (A^2/O) bioreactor biological nutrient removal combined treatment

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Characterization of Microstructure, Strength, and Toughness of Dissimilar Weldments of Inconel 625 and Duplex Stainless Steel SAF 2205

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Acta Metallurgica Sinica(English Letters) 2014年第6期27卷 1018-1030页

作者： r. Sridhar K. Devendranath ramkumar n. Arivazhagan School of Mechanical & Building Sciences VIT University Saraswathy Velu College of Engineering

The dissimilar combinations of Inconel 625 and duplex stainless steel SAF 2205 obtained from manual GTA welding process employing Er2209 and Erni CrMo-3 filler metals have been investigated. Formation of secondary phases at the HAZ of Inconel 625 and grain coarsening at the HAZ of SAF 2205 were witnessed while using these filler wires. The average hardness of Er2209 weldments was found to be greater than Erni CrMo-3 weld. Tensile fracture was observed at the weld zones for both the fillers. Impact test trials showed brittle mode of fracture on employing Er2209 filler and mixed（ductile–brittle） mode of fracture while using Erni CrMo-3 filler. Further optical microscopy and SEM/EDS analysis were carried out across the weldments to investigate the structure–property relationships.

关键词： Inconel 625 Duplex stainless steel SAF 2205 Dissimilar metal welding Microstructure Mechanical characterization

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A HYBrID APPrOACH FOr MInIMIZInG MAKESPAn In PErMUTATIOn FLOWSHOP SCHEDULInG

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Journal of Systems Science and Systems Engineering 2017年第1期26卷 50-76页

作者： Kannan Govindan r'Balasundaram n.Baskar e.Asokan Center for Sustainable Engineering Operations Management Department of Technology and Innovation University of Southern Denmark Odense M Denmark-5230 Department of Mechanical Engineering K.Ramakrishnan College of Engineering Tiruchirappalli Tamilnadu India Pin-621112 Department of Mechanical Engineering Saranathan College of Engineering Tiruchirappalli Tamilnadu India Pin 620012 Department of Production Engineering National Institute of Technology Tiruchirappalli Tamilnadu India Pin-620015

This work proposes a hybrid approach for solving traditional flowshop scheduling problems to reduce the makespan （total completion time）. To solve scheduling problems, a combination of Decision Tree （DT） and Scatter Search （SS） algorithms are used. Initially, the DT is used to generate a seed solution which is then given input to the SS to obtain optimal / near optimal solutions of makespan. The DT used the entropy function to convert the given problem into a tree structured format / set of rules. The SS provides an extensive investigation of the search space through diversification. The advantages of both DT and SS are used to form a hybrid approach. The proposed algorithm is tested with various benchmark datasets available for flowshop scheduling. The statistical results prove that the proposed method is competent and efficient for solving flowshop problems.

关键词： Flowshop scheduling makespan decision tree algorithm scatter search algorithm hybrid algorithm

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Electrodeless plasma thrusters for spacecraft: a review

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Plasma Science and Technology 2017年第8期19卷 1-24页

作者： S n BATHGATE M M M BILEK D r MCKEnZIE Applied and Plasma Physics School of PhysicsUniversity of Sydney

The physics of electrodeless electric thrusters that use directed plasma to propel spacecraft without employing electrodes subject to plasma erosion is reviewed. Electrodeless plasma thrusters are potentially more durable than presently deployed thrusters that use electrodes such as gridded ion,Hall thrusters, arcjets and resistojets. Like other plasma thrusters, electrodeless thrusters have the advantage of reduced fuel mass compared to chemical thrusters that produce the same thrust. The status of electrodeless plasma thrusters that could be used in communications satellites and in spacecraft for interplanetary missions is examined. Electrodeless thrusters under development or planned for deployment include devices that use a rotating magnetic field; devices that use a rotating electric field; pulsed inductive devices that exploit the Lorentz force on an induced current loop in a plasma; devices that use radiofrequency fields to heat plasmas and have magnetic nozzles to accelerate the hot plasma and other devices that exploit the Lorentz force. Using metrics of specific impulse and thrust efficiency, we find that the most promising designs are those that use Lorentz forces directly to expel plasma and those that use magnetic nozzles to accelerate plasma.

关键词： spacecraft a review propellant Lorentz thrust rotating radiofrequency erosion presently exploit

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Effects of Strain rate and Deformation Temperature on Microstructures and Hardness in Plastically Deformed Pure Aluminum

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Journal of Materials Science & Technology 2011年第1期27卷 1-7页

作者： F. Huang n.r. Taot K. Lu Shenyang national Laboratory for Materials Science Institute of Metal Research Chinese Academy of Sciences Shenyang110016 China

The microstructures and hardness of pure Al samples subjected to plastic deformation with different tem- peratures and strain rates were investigated. The results showed that the strain-induced grain refinement is significantly benefited by increasing strain rate and reducing deformation temperature. The saturated size of refined subgrains in Al can be as small as about 240 nm in cryogenic dynamic plastic deformation （DPD）. Grain boundaries of the DPD Al samples are low-angle boundaries due to suppression of dynamic recovery during deformation. Agreement of the measured hardness with the empirical Hall-Petch relation extrapolated from the coarse-grained Al implies that the low-angle boundaries can contribute to strengthening as effective as the conventional grain boundaries.

关键词： Dynamic plastic deformation Microstructure Hardness Strain rate Temperature

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Structural,dielectric and electrical properties of bismuth magnesium tantalate electronic system

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Journal of Magnesium and Alloys 2019年第4期7卷 628-636页

作者： Sarbasri Halder Satyanarayan Bhuyan r.n.P.Choudhary Department of Electronics and Communication Engineering Siksha‘O’AnusandhanDeemed to be UniversityBhubaneswar 751030India Department of Physics Siksha‘O’AnusandhanDeemed to be UniversityBhubaneswar 751030India

The lead-free dielectric compound Bi(Mg2/3Ta1/3)O3(BMT)has been synthesized at high temperature by a low-cost solid-state *** X-ray diffraction(XrD)technique reveals that the fabricated sample has an orthorhombic crystal *** scanning electron microscope(SEM)image displays the uniform distribution of grains on the surface of the *** dielectric parameters(permittivity(εr),and loss tangent(tanδ)are studied over a wide range of temperature(150-500℃)and frequency(1 kHz-1 MHz).The temperature dependent conductivity plot follows Universal Johnson’s power *** complex impedance and modulus spectrum illustrate the electrical behavior of the compound at various frequency and *** nyquist spectra show the presence of the effect of grain and grain boundary in the synthesized *** grain resistance value declines with the rise in temperature that shows the presence of a negative temperature coefficient(nTCr)behavior in the *** complex modulus spectra display the occurrence of the conduction mechanism in the *** reported compound has a relative dielectric constant and loss of 22×10^3 and 1.8 respectively at 1 kHz frequency and 500℃,thus becoming an efficient applicant for dielectric applications that can operate at higher temperatures.

关键词： XrD Impedance spectroscopy Conductivity Conduction

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Free vibration and transient response of double curved beams connected by intermediate straight beams

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Applied Mathematics and Mechanics(English Edition) 2025年第1期46卷 37-62页

作者： r.A.JAFArI-TALOOKOLAEI H.GHAnDVAr E.JUMAEV S.KHATIr T.CUOnG-LE School of Mechanical Engineering Babol Noshirvani University of Technology Department of Mechanical Engineering Faculty of Engineering New Uzbekistan University University of Business and Science Center for Engineering Application and Technology Solutions Ho Chi Minh City Open University

This paper investigates the free vibration and transient response of interconnected structures including double curved beams and intermediate straight beams,which are all constructed from functionally graded porous(FGP) materials. The strain potential and kinetic energies of each beam along with the work done by the external force are calculated. Additionally, a higher-order beam element is introduced to derive stiffness and mass matrices, along with the force vector. The curved and straight beams are discretized, and their assembled stiffness, mass matrices, and force vectors, are *** conditions at the joints are used to derive the total matrices of the entire structure. Subsequently, the natural frequencies and transient response of the system are determined. The accuracy of the mathematical model and the self-developed computer program is validated through the comparison of the obtained results with those of the existing literature and commercial software AnSYS, demonstrating excellent ***, a comprehensive study is conducted to investigate the effects of various parameters on the free vibration and transient response of the considered structure.

关键词： Kinetic energy

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Determination of the physical and interaction properties of sorghum grains:Application to computational fluid dynamics-discrete element method simulations of the fluid dynamics of a conical spouted bed

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Particuology 2021年第1期19卷 91-101页

作者： J.n.M.Batista D.A.Santos r.Bettega Federal University of São Carlos Department of Chemical EngineeringSPBrazil Institute of Chemistry Federal University of GoiásGOBrazil

Computational simulation is an important tool for design and improvement of industrial *** fluid dynamics(CFD)coupled with the discrete element method(DEM)has been applied to simulate drying equipment that usually involves gas-solid *** reliable results of CFD-DEM simulations,the properties related to the interactions of the material within the industrial equipment,such as the restitution or friction coefficients,must be *** this study,CFD-DEM was applied to simulate the fluid dynamics inside a conical spouted bed operating with sorghum *** physical properties of the particulate phase and the particle-particle and particle-wall interaction parameters were determined by the direct measurement approach and applied to *** interaction parameters were experimentally determined,including the particle-particle interaction parameters ofη=0.46,μ^(S)=0.79,andμ_(r)=0.70,and the particle-wall interaction parameters ofη=0.56,μ_(S)=0.75,andμ_(r)=*** simulated minimum spouting velocity and characteristic curves were compared with the experimental *** was good agreement between the simulated and experimental results.

关键词： restitution coefficient Static friction coefficient rolling friction coefficient CFD DEM

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Exploring the vacuum ultraviolet photochemistry of astrochemically important triatomic molecules

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national Science review 2023年第8期10卷 243-259页

作者： Yao Chang Michael n.r. Ashfold Kaijun Yuan Xueming Yang State Key Laboratory of Molecular reaction Dynamics and Dalian Coherent Light Source Dalian Institute of Chemical Physics Chinese Academy of Sciences School of Chemistry University of Bristol University of Chinese Academy of Sciences Hefei national Laboratory Department of Chemistry College of Science Southern University of Science and Technology

The recently constructed vacuum ultraviolet(VUV) free electron laser(FEL) at the Dalian Coherent Light Source(DCLS) is yielding a wealth of new and exquisitely detailed information about the photofragmentation dynamics of many small gas-phase molecules. This review focuses particular attention on five triatomic molecules—H2O, H2S, CO2, OCS and CS2. Each shows excitation wavelength-dependent dissociation dynamics, yielding photofragments that populate a range of electronic and(in the case of diatomic fragments) vibrational and rotational quantum states, which can be characterized by different translational spectroscopy methods. The photodissociation of an isolated molecule from a well-defined initial quantum state provides a lens through which one can investigate how and why chemical reactions occur, and provides numerous opportunities for fruitful, synergistic collaborations with high-level ab initio quantum chemists. The chosen molecules, their photofragments and the subsequent chemical reaction networks to which they can contribute are all crucial in planetary atmospheres and in interstellar and circumstellar environments. The aims of this review are 3-fold: to highlight new photochemical insights enabled by the VUV-FEL at the DCLS, notably the recently recognized central atom elimination process that is shown to contribute in all of these triatomic molecules; to highlight some of the potential implications of this rich photochemistry to our understanding of interstellar chemistry and molecular evolution within the universe; and to highlight other and future research directions in areas related to chemical reaction dynamics and astrochemistry that will be enabled by increased access to VUV-FEL sources.

关键词： vacuum ultraviolet photochemistry photodissociation free electron laser interstellar chemistry chemistry of planetary atmospheres

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Various flows of black and grey particles produced in Mg-emulsion collisions at 4.5 A GeV/c

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Chinese Physics C 2011年第1期35卷 40-43页

作者：高雁刘福虎 n.n.Abd Allah r.Bekmirzaev Department of Physics Xinzhou Normal University Institute of Theoretical Physics Shanxi University Department of Physics Faculty of ScienceSohag UniversitySohagEgypt nuclear Physics Department Djizak State Pedagogical InstituteDjizzak 708000Uzbekistan

Various flow phenomena of black particles （b-particles） and grey particles （g-particles） produced in magnesium-emulsion （Mg-Em） collisions at 4.5 A GeV/c are reported. These flows are directed and elliptic transverse flows （v1 and v2） related by the azimuthal angle （φ）, directed and elliptic reaction plane flows （vr1 and vr2） related by the projected angle （φ） on the reaction plane, and directed and elliptic polar direction flows （vp1 and vp2） related by the polar angle （）. We extract absolute flows as the direct experimental values minus the isotropic theoretical values. The dependence of the various flows on the target particle multiplicity and on the angles （ ,φ,φ） is investigated. Our results show that the dependence of b-particle flows on the target size is obvious and for heavy targets the dependence on target particle multiplicity is slight. Compared with b-particles, g-particles have a slight dependence on the target size and target particle multiplicity.

关键词： various flows absolute flows b- and g-particles Mg-Em collisions

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