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Ocean ecosystem discrete time dynamics generated by l-Vol terra operators

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International Journal of Biomathematics 2019年第2期12卷 77-100页

作者： u.A.Rozikov s.K.shoyimardonov Institute of Mathematics 81Mirzo Ulug'bek Str.100125TashkentUzbekistan Department of Higher Mathematics Tashkent university of Information Technologies(Named After)Muhammad al-Khwarizmi TashkentUzbekistan

We consider a discrete-time dynamical system generated by a nonlinear operator(with four real parameters a,b,c,d)of ocean *** find conditions on the parameters under which the operator is reduced to a l-Volterra quadratic stochastic operator mapping two-dimensional simplex to *** show that if cd(c+d)=0,then(under some conditions on a,b)this l-Volterra operator may have up to three or a countable set of fixed points;if cd(c+d)≠0,then the operator has up to three fixed *** on the parameters,the fixed points may be attracting,repelling or saddle *** limit behaviors of trajectories of the dynamical system are *** is shown that independently on values of parameters and on initial(starting)point,all trajectories ***,the operator(dynamical system)is *** give some biological interpretations of our results.

关键词： Quadratic stochastic operator Volterra operator l-Volterra operator ecosystem modeling

Application of Reactive Ion Etching to the Fabrication of Microstructure on Mo/si Multilayer

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Chinese Physics Letters 1999年第9期16卷 665-666页

作者： LE Zi-chun L.Dreeskornfeld s.Rahn R.segler u.Kleineberg u.Heinzmann Institute of Atomic and Molecular Physics Jilin UniversityChangchun 130012 Fakultät für Physik Universität BielefeldUniversitatsstraβe 25D-33615 BielefeldGermany

Mo/si muitilayer mirrors(30 periods,doublelayer thickness 7nm)with the AZ-PF514 resist pattern whose smallest lines and spaces structure was 0.5pm were etched by reactive ion etching(RIE)in a fluorinated *** etch rate,selectivity and etch profile were investigated as a function of the gas mixture,pressure,and plasma rf *** groove depth and the etch proHle were investigated by an atomic force microscope before RIE,after RIE and after resist removal.

关键词： Mo/si smallest selectivity

A study on the Estimation of Prefabricated Glass Fiber Reinforced Concrete Panel strength Values with an Artificial Neural Network Model

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Computers, Materials & Continua 2016年第4期52卷 41-52页

作者： s.A.Yıldızel A.u.Öztürk Manisa Celal Bayar university Engineering FacultyTurkey

In this study,artificial neural networks trained with swarm based artificial bee colony optimization algorithm was implemented for prediction of the modulus of rapture values of the fabricated glass fiber reinforced concrete *** the application of the ANN models,143 different four-point bending test results of glass fiber reinforced concrete mixes with the varied parameters of temperature,fiber content and slump values were introduced the artificial bee colony optimization and conventional back propagation *** and the testing results of the corresponding models showed that artificial neural networks trained with the artificial bee colony optimization algorithm have remarkable potential for the prediction of modulus of rupture values and this method can be used as a preliminary decision criterion for quality check of the fabricated products.

关键词： Neural network glass fiber reinforced concrete glass fiber

Periodic Algebras Generated by Groups

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Algebra Colloquium 2015年第4期22卷 541-554页

作者： s. Albeverio B.A. Omirov u.A. Rozikov Institut fur Angewandte Mathematik and HCM universitat Bonn Bonn Germany Institute of Mathematics 29 Do'rmon Yo'li str. 100125 Tashkent Uzbekistan

We consider algebras with basis numerated by elements of a group G. We fix a function f from G × G to a ground field and give a multiplication of the algebra which depends on f. We study the basic properties of such algebras. In particular, we find a condition on f under which the corresponding algebra is a Leibniz algebra. Moreover, for a given subgroup G of G we define a G-periodic algebra, which corresponds to a G-periodic function f, we establish a criterion for the right nilpotency of a G-periodic algebra. In addition, for （7 = Z we describe all 2Z- and 3Z-periodic algebras. some properties of nZ-periodic algebras are obtained.

关键词： periodic algebra Leibniz algebra group

Biomass energy cost and feasibility of gasifier based biomass power generation system

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International Journal of Agricultural and Biological Engineering 2013年第4期6卷 55-63页

作者： Khambalkar V P Kankal u s Karale D s Gangde C N Department of Farm Power and Machinery College of Agricultural Engineering and Technology and Dr.Panjabrao Deshmukh Agricultural UniversityAkola MS 444104India

The present research work has been carried out on biomass based on 10 kW capacity gasifier power generation system installed at College of Agricultural Engineering and Technology,*** Deshmukh Agricultural university(***),Akola Maharashtra,*** main objectives were to evaluate various costs and benefits involved in the power generation *** costs of energy per unit were calculated for the first year of *** economics of gasifier based power generation system and thereby the feasibility of the system was examined by estimating per unit cost,Net Present Value(NPV),Benefit Cost Ratio(BCR),Internal Rate of Return(IRR)and payback *** discount cash flow method was used to find out the *** the present analysis,three costs viz.,installed capital cost,operation and maintenance cost,and levelised replacement cost were examined for the evaluation of the power generation per *** rate on investment in case of subsidy(Case I)and in case without subsidy(Case II)for installation cost of system was considered as 12.75%.The BCR comes in Case I for operating duration of 22 h,20 h,and 16 h are 1.24,1.18,and 1.13,*** for Case II BCR comes 1.44,1.38,and *** IRR comes in Case I for operating duration of 22 h,20 h,and 16 h are 26%,22%,and 19%,*** for Case II,IRR comes 52%,44%,and 39%for operating duration of 22 h,20 h,and 16 h,*** payback period in the present analysis was worked *** payback period for biomass based gasifier power generation system was observed to be for Case I from three to four years and for Case II it was one to two years.

关键词： cost of biomass energy biomass power generation system discounted cash flow benefit cost ratio net present value payback period internal rate of return

Effectiveness of heat and mass transfer on mixed convective peristaltic motion of nanofluid with irreversibility rate

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Communications in Theoretical Physics 2021年第10期73卷 36-46页

作者： Y Akbar F M Abbasi u M Zahid s A shehzad Department of Mathematics COMSATS University IslamabadIslamabadPakistan Department of Mathematics COMSATS University IslamabadSahiwalPakistan

Entropy generation is one of the key features in analysis as it exhibits irreversibility of the system. Therefore, the present study investigates the entropy generation rate in a mixed convective peristaltic motion of a reactive nanofluid through an asymmetrical divergent channel with heat and mass transfer characteristics. The endorsed nanofluid model holds thermophoresis and Brownian diffusions. Mathematical modeling is configured under the effects of mixed convection, heat generation/absorption and viscous dissipation. A chemical reaction is also introduced for the description of mass transportation. The resulting system of differential equations is numerically tackled by employing the shooting method. The findings reveal that entropy generation rises by improving the Brownian motion and thermophoresis parameters. The temperature of the nanofluid decreases due to rising buoyancy forces caused by the concentration gradient. The concentration profile increases by increasing the chemical reaction parameter. The velocity increases by enhancing the Brownian motion parameter.

关键词： peristaltic flow thermophoresis and Brownian motion mixed convection chemical reaction irreversibility nanofluid

salinity Distribution at Canal Istanbul and Its Possible Impacts on the Northern Marmara sea

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China Ocean Engineering 2020年第6期34卷 881-888页

作者： Şehriban sAÇu Tarkan ERDIK OlgayŞEN Istanbul Technical university MaslakIstanbul 34467Turkey

Turkey has announced its plan to construct a new waterway, Canal Istanbul, parallel to the Bosphorus. In this study,the influence of Canal Istanbul on salinity distribution in the northern Marmara sea is investigated using a previously calibrated 3 D hydrodynamic and salinity model. Moreover, the salinity field of the canal and its propagation are examined based on various meteorological cases. Finally, the flow structure of the canal is determined. It is calculated that at the southern end of the canal, mainly unidirectional flow(from the Black sea to the Marmara sea)occurs during 68% of the simulation period. A two-layer flow is seen only 28% of the time with a weak lower layer flow, whereas this value decreases to 4% at the north end of the canal. In the southward direction(to the Marmara sea), velocities higher than 1.5 m/s are rarely observed along the canal. The average surface salinity difference in the northern Marmara sea due to the construction of the canal is calculated to be smaller than 0.50 ppt. The salinity difference gradually diminishes as water depth increases and after 25 m(from the surface) almost no difference is observed.

关键词： Canal Istanbul Marmara sea salinity distribution hydrodynamic modeling

study of residual stresses and distortions from the Ti6Al4V based thinwalled geometries built using LPBF process

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Defence Technology（防务技术） 2023年第10期28卷 33-41页

作者： Jagatheeshkumar s Raguraman M siva Prasad AVs Nagesha B K Chandrasekhar u Indian Institute of Information Technology Design and Manufacturing KancheepuramChennai 600127India Gas Turbine Research Establishment DRDOBengaluru 560093India Wipro3D Bengaluru560058India

The current paper focuses on the prediction of residual stresses and distortions in the Laser Powder Bed Fusion(LPBF)built Ti6Al4V thin-walled geometries using Ansys Additive Print(AAP)software which employs a layer-by-layer accumulation of inherent strain to calculate the *** and anisotropic strain scaling factors were calibrated initially within the APP software for the Ti6Al4V based single cantilever beam ***,the numerical simulations were performed in APP software and computed the residual stresses and distortions for the varied process parameters including laser power,scan speed and hatch distance while maintaining the layer thickness constant for all the design *** numerical predictions were compared;they were found to match reasonably well with the XRD measurements within the calibrated regime.

关键词： Ti6Al4V Thin-walled geometry Residual stress Inherent strain XRD Ansys additive print

Effect of austenitization temperature on microstructure and mechanical properties of low-carbon-equivalent carbidic austempered ductile iron

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International Journal of Minerals,Metallurgy and Materials 2018年第7期25卷 770-778页

作者： vinayak dakre d.r.peshwe s.u.pathak ajay likhite Department of Metallurgical ＆ Materials Engineering Visvesvaraya National Institute of TechnologyNagpur 440010India

The wear resistances of austempered ductile iron （ADI） were improved through intxoduction of a new phase （carbide） into the ma- txix by addition of chromium. In the present investigation, low-caxbon-equivalent ductile iron （LCEDI）（CE = 3.06%, and CE represents cax- bon-equivalent） with 2.42% chromium was selected. LCEDI was austeintized at two difl＇erent temperatures （900 and 975~C） a^ld soaked for 1 h and then quenched in a salt bath at 325~C for 0 to 10 h. samples were analyzed using optical microscopy and X-ray diffraction. Wear tests were carded out on a pin-on-disk-type machine. The efl＇ect of austenization temperature on the wear resistance, impact strength, and the mi- crostructure was evaluated. A stxucture-property correlation based on the observations is established.

关键词： low carbon equivalent ductile iron (LCEDI) caxbidic austempered ductile iron (CADI) wear test austenitization temperature impact strength