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Effect of size on biaxial flexural strength for cement-based materials by using a triangular plate method

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Frontiers of Structural and Civil Engineering 2022年第8期16卷 1017-1028页

作者： Hakan t tURKER Department of Civil Engineering Bursa Uludag UniversityBursa 16059Turkey

the effect of size on the biaxial flexural strength(BFS)of Portland cement mortar was investigated by using the recently proposed triangular plate method(tPM).An experimental program was conceived to study the size effect by keeping a constant water-cement ratio of 0.485,cement-sand ratio of 1:2.75,and using unreinforced triangular mortar plates of five different thicknesses and seven different side *** BFS of the produced specimens was tested,and variations of BFS depending on specimen thickness and side length were *** results indicated that increases in triangular plate specimen side length and specimen thickness led to a decrease in the BFS of Portland cement *** effect of specimen length increase on BFS was more significant than on the effect of the specimen *** variations in specimens’thickness indicated a deterministic type I size effect,while the variations in specimens’length showed an energetic-statistical type I size effect.

关键词： testing apparatus&methods plain concrete tensile properties biaxial flexural strength triangular plate method

Interaction of 1,3,3-trinitroazetidine(tNAZ)and Zinc——A DFt treatise

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火炸药学报 2020年第5期43卷 477-483,I0001页

作者： Lemi türker Middle East technical University Department of ChemistryüniversitelerEskisehir Yolu No.106800 ankaya/AnkaraTurkey

In order to investigate whether zinc atom is compatible with 1, 3, 3-trinitroazetidine(tNAZ) structure, tNAZ+Zn and 2 tNAZ+Zn composite systems have been considered within the constraints of density functional theory at the level of B3 LYP/6-31++G(d,p) and ωB97 X-D/6-31++G(D,P). In the case of tNAZ+Zn composite the both level of calculations resulted that one of the C-NO2 bonds of tNAZ undergoes bond cleavage. However, as the zinc content decreases by increasing the tNAZ content, C-NO2 bond elongation considerably decreases, although it is still longer than the similar bonds in 2 tNAZ+Zn composite in which zinc, by weight, is 7.14%. In all the cases the zinc atom acquires positive charge. the results indicate that the interfrontier molecular orbital energy gaps(HOMO-LUMO energy difference) of the composites decrease as the zinc content decreases.

关键词： quantum chemistry 1,3,3-trinitroazetidine tNAZ explosive zinc DFt

Quire Interaction of Certain Nitramine type Explosives with Proton--A DFt Study

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火炸药学报 2017年第1期40卷 1-6页

作者： Lemi türker Department of Chemistry Middle East technical University Ankara Turkey 06231

the composites of certain nitramine type explosives,tEtRYL,RDX and EDNA,with proton in vacuum have been considered within the constraints of density functional theory at the level of B3LYP/6-31++G(d,p)(restricted and unrestricted).the results indicate that unexpectedly hydrogen molecule production occurs by the interaction of proton and a hydrogen of CH3(tEtRYL)and CH2(RDX and EDNA)*** a result,a carbocation is generated on the explosive ***,tEtRYL which potentially has many protonation sites were investigated in more detail in vacuum and aqueous *** data reveals that the composite system(tEtRYL+proton)is less stable than tEtRYL protonated on nitramine NH or oxygen of the nitro groups.

关键词： nitramines tEtRYL RDX EDNA proton DFt

Endohedrally Helium-doped CL-20:A DFt treatment

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火炸药学报 2018年第5期41卷 434-440页

作者： Lemi türker department of chemistry Universiteler middle east technical universityAnkara Turkey 062310

In order to investigate whether endohedral He-doping is possible or not in CL-20,a density functional treatment has been carried out at the levels of B3LYP/6-31++G(d,p)and B3PW91/6-31++G(d,p).Some physicochemical and quantum chemical properties of the helium-doped CL-20 (He@CL-20)are compared with the respective values of the parent explosive *** helium doping caused swelling of CL-20cage but no bond rupture *** helium acquired some positive charge.

关键词： CL-20 explosives Helium Endohedral doping density functional

Synergistic fibroblast optimization: a novel nature-inspired computing algorithm

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Frontiers of Information technology & Electronic Engineering 2018年第7期19卷 815-833页

作者： t t DHIVYAPRABHA P SUBASHINI M KRISHNAVENI Department of Computer Science Avinashilingam Institute for Home Science and Higher Education for Women

the evolutionary algorithm, a subset of computational intelligence techniques, is a generic population-based stochastic optimization algorithm which uses a mechanism motivated by biological concepts. Bio-inspired computing can implement successful optimization methods and adaptation approaches, which are inspired by the natural evolution and collective behavior observed in species, respectively. Although all the meta-heuristic algorithms have different inspirational sources, their objective is to find the optimum(minimum or maximum), which is problem-specific. We propose and evaluate a novel synergistic fibroblast optimization(SFO) algorithm, which exhibits the behavior of a fibroblast cellular organism in the dermal wound-healing process. Various characteristics of benchmark suites are applied to validate the robustness, reliability, generalization, and comprehensibility of SFO in diverse and complex situations. the encouraging results suggest that the collaborative and self-adaptive behaviors of fibroblasts have intellectually found the optimum solution with several different features that can improve the effectiveness of optimization strategies for solving non-linear complicated problems.

关键词： Synergistic fibroblast optimization (SFO) Fitness analysis Convergence Benchmark suite Monk's dataset

An Integrative Collaborative Project Approach to Climate-Change Resilience and Urban/Regional Sustainability for the Mexico-Lerma-Cutzamala Hydrological Region

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Open Journal of Civil Engineering 2022年第1期12卷 101-138页

作者： timothy J. Downs Morgan Ruelle Nigel Brissett Ravi Hanumantha Marisa mazari-Hiriart Rob Krueger Edward R. Carr International Development Community & Environment (IDCE) Department Clark University Worcester USA Institute of Ecology National Autonomous University of Mexico (UNAM) Ciudad Universitaria Coyoacán Mexico Environmental & Sustainability Studies Worcester Polytechnic Institute (WPI) Worcester USA Humanitarian Response and Development Lab (HURDL) George Perkins Marsh Institute Clark University Worcester USA

In a rapidly urbanizing world, the social, economic, and ecological complexities of cities require conceptual and operational innovations to enhance climate resilience and sustainability. We describe our Integrative Collaborative Project (ICP) approach to co-create climate resilience in the Mexico-Lerma-Cutzamala Hydrological Region (MLCHR). In recent years, it has suffered from frequent natural disasters, and under climate change scenarios, the intensity and frequency of extreme events, including severe floods, droughts, heat waves and landslides are expected to increase. ICPs are framed as socio-technical capacity building enterprises, with networks operating at multiple scales. the approach differs from other integrative efforts, which tend to be top-down with scant civil society co-ownership, and focus on limited aspects like indicators/assessment, or institutional capacity building. We reimagine all operational stages, from creative thinking, through ethos and concept, assessment, planning, project design, implementation and management, and monitoring and evaluation. the design of ICPs is informed by six integrative domains: 1) project ethos, concept, and framing;2) sectors, topics, and issues;3) spatial and temporal scales;4) stakeholder interests, relationships and capacities;5) knowledge types, models and methods;and 6) socio-technical capacities and networks. Empirically, the approach is based on participatory development practices, pilot project work tackling sustainable water and sanitation in Mexico, and a synthesis of rich experiential knowledge spanning 20 years. the theoretical basis considers a pragmatic knowledge frame, socio-technical transitions literature, and education for social transformation. We describe forward-looking operational details of the Pilot ICP for the Mexico-Lerma-Cutzamala Hydrological Region, with our three-university partnership as catalyst, and a new breed of socio-technical enterprise organization as a key partner, engaging

关键词： Climate-Change Resilience Sustainable Development Urban Regional Mexico City

Performance Analysis of Intelligent Robust Facility Layout Design

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Chinese Journal of Mechanical Engineering 2017年第2期30卷 407-418页

作者： G MOSLEMIPOUR t S LEE Y t LOONG Department of Industrial Engineering Payame Noor University Faculty of Engineering and technology Multimedia University

Design of a robust production facility layout with minimum handling cost （MHC） presents an appropriate approach to tackle facility layout problems in a dynamic volatile environment, in which product demands randomly change in each planning period. the objective of the design is to find the robust facility layout with minimum total material handling cost over the entire multiperiod planning horizon. this paper proposes a new mathematical model for designing robust machine layout in the stochastic dynamic environment of manufacturing systems using quadratic assignment problem （QAP） formulation. In this investigation, product demands are assumed to be normally distributed random variables with known expected value, variance, and covariance that randomly change from period to period. the proposed model was verified and validated using randomly generated numerical data and benchmark examples. the effect of dependent product demands and varying interest rate on the total cost function of the proposed model has also been investigated. Sensitivity analysis on the proposed model has been performed. Dynamic programming and simulated annealing optimization algorithms were used in solving the modeled example problems.

关键词： Robust layout Dynamic stochastic environment Manufacturing system Dynamic programming

Effect of magnesium on FOX-7 and its tautomers-A DFt treatment

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Defence technology（防务技术） 2018年第3期14卷 179-187页

作者： Lemi türker Middle East technical University Department of Chemistry üniversiteler

FOX-7 and its cisoid and transoid 1,5-tautomers as well as magnesium composites of all have been investigated quantum chemically within the restrictions of density functional theory(B3 LYP/6 e311ttG(d,p)). Certain physico-chemical and quantum chemical properties, energies, stabilities,calculated IR and UV-VIS spectra are discussed. the influence of magnesium atom is investigated. It has been found that in FOX-7 composites the magnesium is not a silent ingredient, but interacts with the organic constituents.

关键词： FOX-7 镁原子 DFt 物理化学药品性质稳定性成分外力

A density functional study on some cyclic N_(10) isomers

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Defence technology（防务技术） 2019年第2期15卷 154-161页

作者： Lemi türker Middle East technical University Department of Chemistry üniversiteler

Polynitrogen compounds, comprising only nitrogen atoms, are rare. they are considered as promising candidates of clean(green) high energy density materials because of their high energy content and their sole decomposition product is N_2. Extending the previous work which was on cyclic N_8 isomers, in this study some cyclic N_(10) isomers having 1-4 cycles are considered within the limitations of density functional theory at the levels of B3LYP/6-311++G(d,p) and B3LYP/cc-PVtZ. Some of the structures,including the monocyclic one, decompose by eliminating certain number of N_2 units while some remain intact. All the stable isomers(1-3, 6-8) investigated presently are highly endothermic that they are candidates for clean high energy materials. Certain quantum chemical properties, IR and UV-VIS spectra as well as the specific impulse values for the stable structures are reported.

关键词： Nitrogen Polynitrogen Density functional theory Isomers N10