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Optimization of Strength Properties of Reactive Powder Concrete by Response Surface methodology

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Journal of Shanghai Jiaotong university(Science) 2024年第5期29卷 900-908页

作者： SAKTHIESWARAn n. mOORTHY n. REnISHA m. CHInnADURAI m. Department of Civil Engineering E.G.S.Pillay Engineering CollegeNagapattinam611002TamilnaduIndia Department of Science and Humanities E.G.S.Pillay Engineering CollegeNagapattinam611002TamilnaduIndia Department of Computer Science and Engineering E.G.S.Pillay Engineering CollegeNagapattinam611002TamilnaduIndia

The main objective of this study is to optimize the fresh and strength properties of reactive powder concrete incorporated with industrial by-products like ultra-fine ground granulated blast furnace slag as cement substitute and added with coal bottom ash and recycled concrete fines as partial replacement of quartz sand by response surface methodology through design of experiment *** four responses n.m.ly slump,compressive strength(C-28),flexural strength(F-28),and split-tensile strength(S-28)after 28 days of curing period were *** statistical study on the reactive powder concrete includes the modeling of regression,normal probability plots,surface plot analysis,and optimization of process *** regression.m.dels of the considered responses(slump,C-28,F-28,and S-28)were *** results obtained from the analysis of variance(AnOVA)and Pareto chart were used to determine the statistical significance of the process *** influence of the variables on the responses was studied by means of the surface plot *** optimal proportion of the variables against the responses was obtained through optimization *** resulted regression equations were in the form of second-order polyn.m.al equation and the prediction of strength properties was found to be in line with the experimental *** difference of proportion of variance indicated that only 0.43%,6.42%,5.15%,and 9.7%of deviations cannot be expressed by the *** AnOVA and Pareto charts represented the high significance and appropriateness of the linear term of slump response and the two-way interaction term of strength *** results of the optimization response revealed the optimal proportions of recycled concrete fines and coal bottom ash as 19.15%and 7.02%,respectively.

关键词： reactive powder concrete mechanical properties fresh properties statistics study coal bottom ash

Efficiency enhancement of building multi-layer solar collector with SiO2–TiO2 hybrid nanofluids

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Building Simulation 2023年第10期16卷 1851-1862页

作者： n.n.m.Zawawi W.H.Azmi Z.A.A.majid R.A.Rahim H.m.Ali Lebuhraya Tun Razak Centre for Research in Advanced Fluid and Processes26300GambangKuantanPahangMalaysia Faculty of mechanical and Automotive Engineering Technology Universiti Malaysia PahangPekanPahang26600Malaysia Kulliyyah of Allied Health Sciences International Islamic University of MalaysiaBandar Indera Mahkota25200KuantanPahangMalaysia ECE Department Kulliyyah of EngineeringInternational Islamic University MalaysiaJalan GombakKuala LumpurMalaysia mechanical Engineering Department King Fahd University of Petroleum and MineralsDhahran31261Saudi Arabia Interdisciplinary Research Center for Renewable Energy and Power Systems(IRC-REPS) King Fahd University of Petroleum and MineralsDhahran31261Saudi Arabia

Due to the depletion of conventional energy sources and its limitless resources,solar energy is currently being considered as a viable alternative,especially for water heating *** thermal performance of multilayer solar collectors for water heating systems can be improved further by introducing hybrid nanofluids as advanced *** study demonstrates the utilisation of hybrid nanofluids in heating systems by employing a multilayer absorber solar *** SiO2–TiO2 hybrid nanofluids at volume concentrations up to 2.0%were tested at various flow rates(1.7 to 3.7 LPm)and solar radiation intensities(250 to 1000 W/m2).The thermal performance of the solar collector was assessed by measuring the temperature variation,heat loss,and overall efficiency of the *** the optimal volume concentration,the temperature difference for solar collectors employing SiO2–TiO2 hybrid nanofluids increased *** optimal volume concentration of 1.5%yields a maximum temperature difference of 9.5°*** addition,the efficiency and fluid temperature of the solar collector containing hybrid nanofluids have been enhanced by 22%and 37%,*** SiO2–TiO2 hybrid nanofluids with the optimal volume concentration of 1.5%were therefore recommended for maximum efficiency in the solar collector.

关键词： solar collector hybrid nanofluids solar water heating system solar simulator thermal efficiency

The Influence of the Dependence of Surface Energy Coefficient to Temperature in the Proximity model

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Chinese Physics Letters 2013年第4期30卷 55-59页

作者： m.Salehi O.n.Ghodsi Sciences Faculty Department of PhysicsQaemshahr BranchIslamic Azad UniversityP.O.Box 163QaemshahrIran Sciences Faculty Department of PhysicsUniversity of MazandaranP.O.Box 47415-416BabolsarIran

We introduce a new surface energy coefficient in proximity formalism,which is dependent on temperature,and apply it to a systematic study of barrier height and *** proximity model can effectively predict the barrier heights and positions,as well as the fusion cross sections,over a wide range of incident energies,especially in light-heavy nuclei interaction.

关键词： interaction. proximity apply

Site Selective Excitation and Energy Transfer in LiKGdF_5 Crystal Co-doped with Er^(3+) and Tb (3+)

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Journal of Rare Earths 2004年第1期22卷 22-26页

作者：尹民 Khaidukov n.m.Krupa J C Structure Research Laboratory Kurnakov Institute of General and Inorganic Chemistry Institut de Physique nucléaire

Crystals of LiKGdF 5∶Er 3+, Tb 3+ grown by the hydrothermal synthesis technique with concentrations of 2% and 0.4% were analysed. By using site selective excitation.m.asured at low temperature, luminescence and excitation spectra from Er 3+ and Tb 3+ ions embedded in LiKGdF 5 were clearly separated. The lifetimes of the emitting levels 4S 3/2 of Er 3+ and 5D 4 of Tb 3+ were also determined. Following the site selective spectroscopy study, the dominant energy transfer process from Tb 3+ to Er 3+ in the crystal was then investigated via transient experiments.

关键词： optics condensed matter physics energy transfer luminescence LiKGdF 5∶Er3+, Tb3+ rare earths

Cross-sectional warping and precision of the first-order shear deformation theory for vibrations of transversely functionally graded curved beams

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Applied mathematics and mechanics(English Edition) 2023年第12期44卷 2109-2138页

作者： U.n.ARIBAS m.AYDIn.m.ATALAY m.H.OmURTAG Department of Civil Engineering Istanbul Medipol UniversityIstanbul 34810Türkiye

The warping may become an important factor for the precise transverse vibrations of curved ***,the first aim of this study is to specify the structural design parameters where the influence of cross-sectional warping becomes great and the first-order shear deformation theory lacks the precision *** outof-plane vibrations of the first-order shear deformation theory are compared with the warping-included vibrations as the curvature and/or thickness increase for symmetric and asymmetric transversely-functionally graded(TFG)curved *** second aim is to determine the influence of design parameters on the *** circular/exact elliptical beams are formed via curved mixed finite elements(mFEs)based on the exact curvature and *** stress-free conditions are satisfied on three-dimensional(3D)constitutive *** variation of functionally graded(FG)material constituents is considered based on the power-law *** cross-sectional warping deformations are defined over a displacement-type FE *** warping-included mFEs(W-mFEs)provide satisfactory 3D structural characteristics with smaller degrees of freedom(DOFs)compared with the brick *** newmark method is used for the forced vibrations.

关键词： mixed finite element(mFE) free vibration forced vibration warping exact elliptical beam functionally graded(FG)beam

Theoretical study on the favored alpha-decay half-lives of deformed nuclei

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Chinese Physics C 2021年第12期45卷 140-146页

作者： m.Hassanzad O.n.Ghodsi Department of Physics Faculty of Basic SciencesUniversity of MazandaranP.O.Box 47416-416BabolsarIran

A systematic study on the a-decay half-lives of nuclei in the range 93≤Z≤118 is performed by employing various versions of proximity *** obtain.m.re reliable results,deformation terms are included up to hexadecapole(β_(4))in the spherical-deformed nuclear and Coulomb interaction ***,the favored a-de-cay processes in this region are categorized as even-even,odd A,and odd-odd ***,they are grouped into two transitions:ground state to ground state and ground state to isomeric *** to the comparison of their root-mean-square deviations(RmSD's),Bassll and ngo80 have the lowest values and better reproduce experimental ***,by considering preformation probability within the cluster formation.m.del,the results validate the significant reduction in root-mean-square deviations obtained for different versions of ***,the deviation between the calculated and experimental data is detracted.

关键词： alpha-decay deformation proximity potential isomeric state ground state

Evolution of plasma parameters in an Ar-n2/He inductive plasma source with magnetic pole enhancement

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Plasma Science and Technology 2017年第2期19卷 34-42页

作者： maria YOUnUS n U REHmAn.m.SHAFIQ m nAEEm m ZAKA-UL-ISLAm m ZAKAULLAH Department of Physics Plasma Physics LaboratoryQuaid-i-Azam University45320 IslamabadPakistan Plasma Physics Laboratory Department of PhysicsCOMSATS Institute of Information Technology44000 IslamabadPakistan Department of Physics Faculty of ScienceJazan University114 JazanSaudi Arabia

magnetic pole enhanced inductively coupled plasmas （maPE-ICPs） are a promising source for plasma-based etching and have a wide range of material processing applications. In the present study Lan.m.ir probe and optical emission spectroscopy were used to monitor the evolution of plasma parameters in a maPE-ICP Ar-na/He mixture plasma. Electron density （ne） and temperature （Te）, excitation temperature （Texc）, plasma potential （Vp）, skin depth （6） and the evolution of the electron energy probability function （EEPF） are reported as a function of radiofrequency （RF） power, pressure and argon concentration in the mixture. It is observed that ne increases while Te decreases with increase in RF power and argon concentration in the mixture. The emission intensity of the argon line at 750.4 nm is also used to monitor the variation of the ‘high-energy tail＇ of the EEPF with RF power and gas pressure. The EEPF has a ‘bi-maxwellian＇ distribution at low RF powers and higher pressure in a pure n2 discharge. However, it evolves into a ‘maxwellian＇ distribution at RF powers greater than 70 W for pure n2, and at 50 W for higher argon concentrations in the mixture. The effect of argon concentration on the temperatures of two electron groups in the ‘bi-maxwellian＇ EEPF is examined. The temperature of the low-energy electron group TL shows a decreasing trend with argon addition until the ‘thermalization＇ of the two temperatures occurs, while the temperature of high-energy electrons Ta decreases continuously.

关键词： maPE-ICP Lan.m.ir probe OES EEPF

Analysis of electron energy distribution function in a magnetically filtered complex plasma

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Chinese Physics B 2013年第4期22卷 324-329页

作者： m K Deka H Bailung n C Adhikary Physical Sciences Division Institute of Advanced Study in Science and Technology Vigyan Path Paschim Boragaon Garchuk Guwahati-781035 Assam India

The electron energy distribution function （EEDF） for a magnetically filtered dusty plasma is studied in a dusty double plasma device where the electron energy can be varied from 0.15 eV to ～ 2.8 eV and plasma density from 10 6 cm-3 to 10 9cm-3 . The characteristics of EEDF for these ranges of plasma parameters are investigated in a pristine plasma as well as in a dusty plasma. The results show that in the presence of dust, there is a drastic modification in EEDF patterns in a plasma with higher electron temperature and density than those in a low temperature and low density plasma produced by the magnetic filter.

关键词： dusty plasma magnetic filter electron energy distribution function

Statistical Treatment of Low-Energy nuclear Level Schemes

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Communications in Theoretical Physics 2007年第2期47卷 303-308页

作者： m. Gholami m. Kildir A.n. Behkami Chemistry Departments middle East Technical University Ankara Turkey Physics Department Islamic Azad University Mahabad Iran

The level density parameter and the back shift energy E1 are determined for nuclei with A-values across the whole periodic table from fits to complete level schemes at low excitation energy near the neutron binding energies. We find that the energy back shift EI shows complicated behavior and depends on the type of the nucleus, even-even, odd mass, and odd-odd. The spin cut-off factor has also been investigated for nuclei mentioned above. The results are compared with the previous results and different experimental data on level densities.

关键词： nuclear structure level density parameters nuclear spin cut-off factor