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Microbial calcite,a bio-based smart nanomaterial in concrete remediation

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International Journal of smart and Nano Materials 2010年第1期1卷 28-39页

作者： s.s.Bang J.J.Lippert u.Yerra s.Mulukutla V.Ramakrishnan Department of Chemical and Biological Engineering South Dakota School of Mines and TechnologyRapid CitySD 57701USA Department of Civil and Environmental Engineering South Dakota School of Mines and TechnologyRapid CitySD 57701USA

The concept of developing a biosealant in concrete remediation is based on unique microbial metabolic processes.A common soil microorganism,sporosarcina pasteurii,can induce CaCO_(3) precipitation in the surroundings in response to environmental cues such as high pH and available nutrients and minerals.A new biomolecule,microbial calcite is introduced as a smart nanomaterial for self-healing concrete-its effects on concrete performance were evaluated with regard to surface crack remediation and durability *** crack remediation,*** cells immobilized on porous glass beads,siran^(TM),were applied to cracks and tested for stiffness and compressive *** durability tests,cement mortar beams prepared with bacteria were subjected to freeze-thaw cycles and examined for mean expansions and weight *** performance of the concrete was significantly enhanced by treatment with microbial calcite in simulated concrete cracks and cement mortar beams.

关键词： biosealant microbial calcite smart nanomaterial sporosarcina pasteurii immobilization concrete remediation

Casting properties of AsTM A128 Gr.E1 steel modified with Mn-alloying and titanium ladle treatment

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China Foundry 2021年第3期18卷 199-206页

作者： uğur Gürol Erdal Karadeniz OzanÇoban süleyman Can Kurnaz Gedik Welding Company Ankara Caddesi34906İstanbulTurkey sakarya university Engineering FacultyDepartment of Metallurgical&Materials EngineeringEsentepe Campus54187SakaryaTurkey sakarya university Engineering FacultyDepartment of Mechanical EngineeringEsentepe Campus54187SakaryaTurkey Istanbul Gedik university Engineering FacultyDepartment of Metallurgical&Materials Engineering34876IstanbulTurkey

This work aims to produce a high manganese steel with more refined austenite grains and better wear resistance without sacrificing the toughness and tensile properties by Mn alloying and Ti ladle treatment in comparision to AsTM A128 Gr.E1 steel (1.0C-13Mn) that is mostly used in the mining *** 1.0C-17Mn-xTi alloys (x=0,0.05 and 0.1,in wt.%) were prepared.A relationship was established between the microstructures and mechanical properties of the as-cast and solution annealed *** Ti content increases the stable Ti(CN) phase on and beside the grain boundaries and decreases up to 37% the austenite grain size of the as-cast alloy with 0.10wt.% ***,after solution annealed,optimized titanium content (0.05wt.%) results in significant improvements in wear resistance,hardness,elongation,yield and tensile strengths by 44%,31%,30%,8% and 12%,respectively,except 9% decrease in impact toughness compared to AsTM A 128 Gr.E1 steel without *** results show that 1.0C-17Mn-0.05Ti alloy can be used for parts exposed to high load wear and applied in conditions where relatively high tensile properties with sufficent ductility is needed.

关键词： high manganese steel hadfield steel ladle treatment grain refinement microstructure mechanical properties

THE KACANOV METHOD FOR A NONLINEAR VARIATIONAL INEQuALITY OF THE sECOND KIND ARIsING IN ELAsTOPLAsTICITY

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Chinese Annals of Mathematics,series B 1996年第2期17卷 129-138页

作者： HAN WEIMIN s. JENsEN Department of Mathematics University of Iowa Iowa City IA 52242 U.S.A.Department of Mathematics University of Maryland Baltimore County Baltimore MD 21228 U.S.A.

The authors first prove a convergence result on the Ka(?)anov method for solving generalnonlinear variational inequalities of the second kind and then apply the Kacanov method tosolve a nonlinear variational inequality of the second kind arising in elastoplasticity. In additionto the convergence result, an a posteriori error estimate is shown for the Kacanov iterates. Ineach step of the Ka(?)anov iteration, one has a (linear) variational inequality of the secondkind, which can be solved by using a regularization technique. The Ka(?)anov iteration andthe regularization technique together provide approximations which can be readily computednumerically. An a posteriori error estimate is derived for the combined effect of the Ka(?)anoviteration and the regularization.

关键词： Kacanov method Nonlinear variational inequality of the second kind Convergence Regularization A posteriori error estimate

sIMuLATION OF INVENTORY POLICY FOR PRODuCT WITH PRICE AND TIME-DEPENDENT DEMAND FOR DETERIORATING ITEM

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International Journal of Modeling, simulation, and scientific Computing 2012年第1期3卷 1-30页

作者： D.sHuKLA u.K.KHEDLEKAR R.P.s.CHANDEL s.BHAGWAT Department of Mathematics and statistics Dr.Hari singh Gour Central university sagar M.P.India Department of Mathematics and Computer science Model science College Jabalpur M.P.India Department of Business Management Dr.Hari singh Gour Central university sagar M.P.India

In a declining market for goods,we optimize the net profit in business when inventory management allows change in the selling prices n times over time *** are computing optimal number of changes in prices,respective optimal prices,and optimal profit in each of the cycle for a deteriorating *** paper theoretically proves that for any business setup there exists an optimal number of price settings for obtaining maximum *** results are supported by numerical examples for different setups(data set)and it is found that for every setup the dynamic pricing policy out-performs the static pricing *** our model,the deterioration factor has been taken into *** deteriorated units are determined by the recurrence *** we studied the effect of different parameters on optimal policy with *** managerial purposes,we have provided some“suggested intervals”for choosing parameters depending upon initial demand,which help to predict the best prices and arrival of customers(demand).

关键词： Dynamic pricing deterioration time-dependent price sensitive demand optimal policy optimal number of change in price

The Faddeev knots as stable solitons: Existence theorems

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science China Mathematics 2004年第2期47卷 187-197页

作者： LIN Fanghua & YANG YisongCourant Institute of Mathematical sciences, New York university, New York, New York 10012, u. s. A.school of Mathematics, Institute for Advanced study, Princeton, New Jersey 08540, u. s. A. Department of Mathematics, Polytechnic university, Brooklyn, New York 11201, u. s. A. Courant Institute of Mathematical sciences New York University New York U S A school of Mathematics Institute for Advanced Study Princeton U S A Department of Mathematics Polytechnic University Brooklyn U S A

The problem of existence of knot-like solitons as the energy-minimizing configurations in the Faddeev model, topologically characterized by an Hopf invariant, Q, is considered. It is proved that, in the full space situation, there exists an infinite set s of integers so that for any m ∈ s, the Faddeev energy, E, has a minimizer among the class Q = m; in the bounded domain situation, the same existence theorem holds when s is the set of all integers. One of the important technical results is that E and Q satisfy the sublinear inequality E ≤ C|Q|sup>3/4sup>, where C > 0 is a universal constant, which explains why knotted (clustered soliton) configurations are preferred over widely separated unknotted (multisoliton) configurations when |Q| is sufficiently large.

关键词： knots, Hopf invariant, minimization, solitons.

structural and photoluminescence studies on europium-doped lithium tetraborate(Eu:Li2B4O7)single crystal grown by microtube Czochralski(μT-Cz)technique

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Chinese Physics B 2016年第5期25卷 429-433页

作者： A Kumaresh R Arun Kumar N Ravikumar u Madhusoodanan B s Panigrahi K Marimuthu M Anuradha GRD Centre for Materials Research PSG College of TechnologyCoimbatoreIndia Department of Physics PSG College of TechnologyCoimbatoreIndia Radiation safety Division Indira Gandhi Centre for Atomic ResearchKalpakkamIndia Department of Physics Gandhigram Rural UniversityDindigulIndia PsG Institute of Advanced studies CoimbatoreIndia

Rare earth europium（Eu（3＋））-doped lithium tetraborate（Eu：Li_2B_4O_7） crystal is grown from its stoichiometric melt by microtube Czochralski pulling technique（μT-Cz） for the first time. The grown crystals are subjected to powder x-ray diffraction（PXRD） analysis which reveals the tetragonal crystal structure of the crystals. uV–vis–NIR spectral analysis is carried out to study the optical characteristics of the grown crystals. The crystal is transparent in the entire visible region, and the lower cutoff is observed to be at 304 nm. The existence of BO_3 and BO_4 bonding structure and the molecular associations are analyzed by Fourier transform infrared（FTIR） spectroscopy. The results of excitation and emission-photoluminescence spectra of europium ion incorporated in lithium tetraborate（LTB） single crystal reveal that the observations of peaks at 258,297, and 318 nm in the excitation spectra and peaks at 579, 591, 597, 613, and 651 nm are observed in the emission *** chromaticity coordinates are calculated from the emission spectra, and the emission intensity of the grown crystal is characterized through a CIE 1931（Commission International d＇Eclairage） color chromaticity diagram.

关键词： crystal growth optical material growth from melt photoluminescence study

Ion-acoustic waves at the night side of Titan's ionosphere:higher-order approximation

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Communications in Theoretical Physics 2020年第5期72卷 70-77页

作者： s M Ahmed E R Hassib u M Abdelsalam R E Tolba W M Moslem Department of Mathematics Faculty of ScienceSuez UniversitySuezEgypt Department of Mathematics Faculty of ScienceFayoum UniversityFayoumEgypt Department of Mathematics Rustaq College of EducationOman Centre for Theoretical Physics The British University in Egypt(BUE)El-Shorouk CityCairoEgypt Department of Physics Faculty of SciencePort Said UniversityPort Said 42521Egypt

Nonlinear solitary waves are investigated for a plasma system at the night side of Titan's *** plasma model consists of three positive ions,namely C2H5^+,HCNH^+,and C3H5^+,as well as Maxwellian *** basic set of fluid equations is reduced to a Korteweg de-Vries(KdV)equation and linear inhomogeneous higher order KdV(LIHO-KdV)*** solitary wave solutions of both equations are obtained using a renormalization *** solitary waves'existence region and the wave profile are investigated,and their dependences on the plasma parameters at the night side of Titan's ionosphere are *** solitary waves'phase velocities are subsonic or supersonic,and the propagating pulses are usually *** effect of higher-order corrections on the perturbation theory is *** is found that the higher-order contribution makes the amplitude slightly taller,which is suitable for describing the solitary waves when the amplitude augments.

关键词： plasmas ion-acoustic waves planets and satellites:atmospheres

superstatistics of Modified Rosen-Morse Potential with Dirac Delta and uniform Distributions

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Communications in Theoretical Physics 2019年第10期71卷 1246-1252页

作者： u.s.Okorie A.N.Ikot G.J.Rampho R.sever Department of Physics AkwaIbom State UniversityIkotAkpadenUyo.Nigeria Department of Physics University of Port HarcourtChobaNigeria Department of Physics University of South AfricaFlorida Park1710South Africa Department of Physics Middle East Technical University06800AnkaraTurkey

We discuss the thermodynamic properties of a modified Rosen-Morse potential using the q-deformed superstatistics approaches. We obtain the partition function with the help of the generalized Boltzmann factor from the modified Dirac delta distribution and uniform distribution. Other thermodynamic function is obtained for the superstatistics of the two distributions considered. We also discuss our results graphically and obtain the ordinary statistical quantities when the deformation parameter tends to zero.

关键词： superstatistics partition function thermodynamic function

Effect of intramolecular energy transfer on the rate of unimolecular isomerization: HCN --HNC

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Chinese Journal of Chemistry 1995年第2期13卷 141-149页

作者： ZHAO, Mei-shan The James Franck Institute, The university of Chicago, Chicago, IL 60637, u.s.A. The James Franck Institute The University of Chicago Chicago IL 60637 U.S.A.

This paper reports calculations of the rate of isomerization of HCN - HCN based on the theory of Gary and Rice as extended by Zhao and Rice. The major task is to determine the effect of intramolecular energy transfer on the prediction of the rate of isomerization. Both the full three-dimensional (3D) system and the reduced two-dimensional (2D) system obtained from freezing CN bond at 1.159 A are analyzed to check the validity of the freezing bond approximation. Meanwhile, RRKM rates are calculated to test RRKM choice of the transition state by comparing to Gary-Rice three-state model. The comparison shows that the rates from 2D model and 3D model are differing up to 20% with 2D rates consistently larger. The intramolecular energy transfer modifies the isomerization rate for HCN system up to 30% that is modestly small by the expectation. The isomerization rate predicted from RRKM theory is greater than those of Gary-Rice three-state model theory up to 65%, and it overstimates the rates under all considerations, including the contribution from intramolecular energy transfer, for the studied system by about a factor of 2.

关键词： Nonlinear dynamics bottleneck separatrix Poincare surface of section quasiperi-odic chaotic unimolecular isomerization rate.