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Tensile strength and failure behavior of rock-mortar interfaces: Direct and indirect measurements

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第1期16卷 41-55页

作者： Ghasem Shams Patrice Rivard Omid moradian Civil Engineering and Building Engineering Department Universitéde SherbrookeSherbrookeQuébecCanada Department of Earth Sciences Swiss Federal Institute of Technology(ETH)ZurichSwitzerland Department of Civil and Environmental Engineering Colorado School of MinesGoldenCOUSA

The tensile strength at the rock-concrete interface is one of the crucial factors controlling the failure mechanisms of structures,such as concrete gravity *** the critical importance of the failure mechanism and tensile strength of rock-concrete interfaces,understanding of these factors remains very *** study investigated the tensile strength and fracturing processes at rock-mortar interfaces subjected to direct and indirect tensile *** image correlation(DIC)and acoustic emission(AE)techniques were used to monitor the failure mechanisms of specimens subjected to direct tension and indirect loading(Brazilian tests).The results indicated that the direct tensile strength of the rock-mortar specimens was lower than their indirect tensile strength,with a direct/indirect tensile strength ratio of 65%.DIC strain field data and moment tensor inversions(MTI)of AE events indicated that a significant number of shear microcracks occurred in the specimens subjected to the Brazilian *** presence of these shear microcracks,which require more energy to break,resulted in a higher tensile strength during the Brazilian *** contrast,microcracks were predominantly tensile in specimens subjected to direct tension,leading to a lower tensile *** monitoring of the cracking processes in the rock-mortar interfaces revealed that they show AE precursors before failure under the Brazilian test,whereas they show a minimal number of AE events before failure under direct *** to different microcracking mechanisms,specimens tested under Brazilian tests showed lower roughness with flatter fracture surfaces than those tested under direct tension with jagged and rough fracture *** results of this study shed light on better understanding the micromechanics of damage in the rock-concrete interfaces for a safer design of engineering structures.

关键词： Rock-mortar Rock-concrete Moment tensor inversion(MTI) Acoustic emission(AE) Digital image correlation(DIC) Tensile strength Direct tensile test Brazilian test

Investigating the causes of Lake Urmia shrinkage:climate change or anthropogenic factors?

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Journal of Arid Land 2023年第4期15卷 424-438页

作者： Mehri SHAMS GHAHFAROKHI Sogol moradian Department of Social Sciences University of IsfahanIsfahan 81746-73441Iran Department of Civil Engineering University of GalwayGalway H91TK33Ireland

In the current scenario,Lake Urmia,one of the vastest hyper saline lakes on the Earth,has been affected by serious environmental *** different satellite images and observational data,this study investigated the changes in the lake for the period 1970–2020 based on the effects of climate change and several human-induced processes on Lake Urmia,such as population growth,excessive dam construction,low irrigation water use efficiency,poor water resources management,increased sediment flow into the lake,and lack of political and legal *** results indicated that between 1970 and 1997,the process of change in Lake Urmia was slow;however;the shrinkage was faster between 1998 and 2018,with about 30.00%of the lake area *** per the findings,anthropogenic factors had a much greater impact on Lake Urmia than climate change and prolonged drought;the mismanagement of water consumption in the agricultural sector and surface and underground water withdrawals in the basin have resulted in a sharp decrease in the lake's *** challenges have serious implications for water resources management in Lake Urmia ***,we provided a comprehensive overview of anthropogenic factors on the changes in Lake Urmia along with existing opportunities for better water resources management in Lake Urmia *** study serves as a guideline framework for climate scientists and hydrologists in order to assess the effects of different factors on lake water resources and for decision-makers to formulate strategies and plans according to the management task.

关键词： Lake Urmia lake shrinkage climate change population growth dam construction water resources management

Comparative analysis of multi criteria decision making techniques for material selection of brake booster valve body

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Journal of Traffic and Transportation Engineering(English Edition) 2019年第5期6卷 526-534页

作者： Milad moradian Vahid Modanloo Soroush Aghaiee Department of Mechanical Engineering Faculty of EngineeringUrmia University

Braking system is one of the most critical parts in a vehicle,and one of the main components of this system is brake booster valve body which plays a significant role in safety standards of the *** working conditions under the hood of the vehicle necessitate the valve body to have some special *** component should have high mechanical strength and the ability to maintain this strength at elevated *** the other hand,lower weight and lower cost are always desirable in *** material selection for the valve body is very important and should satisfy the aforementioned *** order to select the best material for a large number of alternatives considering many different criteria,multi criteria decision making(MCDM) methods are used in this *** weighting of criteria is carried out by entropy and analytic hierarchy process(AHP) methods and a combination of these two techniques are used as the final ***,TOPSIS and VIKOR methods are used in this paper for selecting the best material for braking booster valve *** alternative materials were ranked using these methods and the results of the analysis were compared using Spearman’s rank ***-gf35(PET reinforced with 35 wt% glass fiber) was found to be the best material for the valve *** to the desirability of the results,the results of this study can be used in automotive industry in order to enhance the material selection process.

关键词： Brake booster Valve body Material selection Weighting Ranking

Experimental investigation and development of new correlation for influences of temperature and concentration on dynamic viscosity of MWCNT-SiO2(20-80)/20W50 hybrid nano-lubricant

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Chinese Journal of Chemical Engineering 2018年第1期26卷 152-158页

作者： Kazem Motahari Mohammad Abdollahi Moghaddam Mojtaba moradian Department of Chemical Engineering Faculty of EngineeringArak UniversityArak 38156-8-8349Iron Young Researchers and Elite Club Malayer BranchIslamic Azad UniversityMalayerIran

In current research, MWCNT-SiO2/oil hybrid nano-lubricant viscosity is experimentally examined. By dispersing 0.05%, 0.1%, 0.2%, 0.4%, 0.8% and 1% volume of MWCNTs and SiO2 nanopartide into the engine oil SAE 20W50, the temperature and solid volume fraction consequences were studied. At 40 to 100 ℃ temperature, the viscosities were assessed. The results indicated Newtonian behavior for the hybrid nano-lubricant. Moreover, solid volume fraction augmentation and temperature enhanced the viscosity enhancement of hybrid nano-lubricant. At highest solid volume fraction and temperature, nano-lubricant viscosity was 171% greater compared to pure 20W50. Existed models lack the ability to predict the hybrid nano-lubricant viscosity. Thus, a new correlation regarding solid volume fraction and temperature was suggested with R-squared of 0.9943.

关键词： Hybrid nano-lubricant Dynamic viscosity Temperature Solid volume fraction New correlation

Moment tensor and stress inversion solutions of acoustic emissions during compression and tensile fracturing in crystalline rocks

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Journal of Rock Mechanics and Geotechnical Engineering 2023年第10期15卷 2778-2786页

作者： Zihua Niu Bing Qiuyi Li Omid moradian Department of Earth Sciences Swiss Federal Institute of Technology(ETH)Zurich8006Switzerland Department of Civil and Environmental Engineering Western UniversityLondonONN6A 3K7Canada Department of Civil and Environmental Engineering Colorado School of MinesGoldenCO80401USA

We investigate the accuracy and robustness of moment tensor(MT)and stress inversion solutions derived from acoustic emissions(AEs)during the laboratory fracturing of prismatic Barre granite ***-cut flaws in the specimens introduce a complex stress field,resulting in a spatial and temporal variation of focal ***,we consider two experimental setups:(1)where the rock is loaded in compression to generate primarily shear-type fractures and(2)where the material is loaded in indirect tension to generate predominantly tensile-type *** each test,we first decompose AE moment tensors into double-couple(DC)and non-DC terms and then derive unambiguous normal and slip vectors using k-means clustering and an unstructured damped stress inversion *** explore temporal and spatial distributions of DC and non-DC events at different loading *** majority of the DC and the tensile non-DC events cluster around the pre-cut flaws,where macro-cracks later *** of stress inversion are verified against the stress field from finite element(FE)modeling.A good agreement is found between the experimentally derived and numerically simulated stress *** the best of the authors’knowledge,this work presents the first case where stress inversion methodologies are validated by numerical simulations at laboratory scale and under highly heterogeneous stress distributions.

关键词： Induced seismicity Acoustic emission(AE) Moment tensor(MT)inversion Stress inversion Finite element(FE)modeling

Geology and geochemical evaluation of Taftan Volcano, Sistan and Baluchestan Province, southeast of Iran

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Chinese Journal Of Geochemistry 2008年第4期27卷 356-369页

作者： Biabangard H. moradian A. Department of Geology Shahid Bahonar University of Kerman Iran

在它的 stratighraphy 的一瞥， Taftan 火山能作为三个组被分类：pre- ， syn -- 并且 volcanic 以后沉积物。pre 暴烈的存款主要由复理层外形和有颜色的 m é lange 建筑群组成。syn 暴烈的存款主要是主要从这座火山的主要身体由碎屑... 详细信息

在它的 stratighraphy 的一瞥， Taftan 火山能作为三个组被分类：pre- ， syn -- 并且 volcanic 以后沉积物。pre 暴烈的存款主要由复理层外形和有颜色的 m é lange 建筑群组成。syn 暴烈的存款主要是主要从这座火山的主要身体由碎屑状的焦性没食子酸和熔岩流组成的 Taftan 火山的产品。volcanic 以后存款主要是从 Taftan 火山的 epiclastic 和重做的材料由于它的侵蚀并且捱过。专业和痕量元素，和从 Taftan 火山在整个岩石的样品上决定的 Sr/Rb 同位素组成证明火山在大陆人边缘被形成。Taftan 火山的整个岩石的同位素组成与 87Sr/86 Sr=0.705326 0.705921。Taftan 火山的 Geochronological 样品由 40K/40 Ar 方法把 6.95 ± 0 .72 的一个年龄范围给了 0.71 ± 0 .03 妈。稀土元素的元素模式被高 LREE 和将近强烈线性的模式为 MREE 描绘到 HREE，建议象橄榄石和辉石那样的特殊矿物质在早 magmatic 阶段结晶然后涉及在下地壳和残余岩浆之间的反应。在 Taftan 火山下面的综合同位素和痕量元素分类学和构造结构由主要岩浆建议了降低外壳的吸收。主要岩浆从异构的披风来源和一个第二等的 petrogenetical 过程产生了。这岩浆能被阿曼海的俯冲在大陆人欧亚大陆板下面影响了。

关键词：地球化学地质火山年代学同化作用

A review of science–policy interface for water governance in the Caspian Sea

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干旱区科学:英文版 2023年第10期15卷 1143-1159页

作者： Apoorva BAMAL Sogol moradian Ali TORABI-HAGHIGHI Agnieszka INDIANA-OLBERT College of Science and Engineering University of GalwayGalway H91 TK33Ireland Ryan Institute University of GalwayGalway H91 TK33Ireland MaREI Research Centre University of GalwayGalway H91 TK33Ireland Eco-HydroInformatics Research Group(EHIRG) Civil EngineeringNational University of Ireland GalwayGalway H91 TK33Ireland Water Energy and Environmental Engineering Research Unit University of OuluOulu FI-90014Finland

Science and policy have been interlinked for decades and perform essential nexus conditions in the governing aspects of environmental *** review paper examines the present challenges in the science–policy interface in terms of water governance in the Caspian Sea and identifies effective conditions that may be used in the current context to enhance the *** evaluation of the science–policy link in the water policy of the Caspian Sea reveals a gap between knowledge producer and governance system,impeding the translation of scientific information into *** and context-dependent solutions make it challenging to establish effective science–policy processes in the Caspian Sea water governance *** a common governing authority,implementing water and resource management regulations,and protecting the natural environment through legal frameworks are crucial steps to address these concerns and ensure sustainable *** among coastal states is essential in environmental,economic,and social aspects of regional ***,the lack of a comprehensive approach,coherent activities,and effective utilization of national and regional power has hindered efforts to halt the environmental degradation of the Caspian *** governments need to recognize their responsibility to protect and utilize the Caspian Sea for present and future generations,considering both environmental and human *** interlinkage of the Caspian Sea water governance with the Organization for Economic Co-operation and Development(OECD)water governance principles offers a framework for policymakers to assess gaps and make necessary amendments to existing *** science–policy interaction,engagement of diverse stakeholders,institutionalizing agreements,and addressing collective action issues are critical for successful water governance.

关键词： resource management Organization for Economic Co-operation and Development water security water governance principle Caspian Sea

Design, synthesis, and nanoengineered modification of spherical graphene surface by layered double hydroxide (LDH) for removal of As (Ⅲ) from aqueous solutions

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Chinese Journal of Chemical Engineering 2023年第1期53卷 374-380页

作者： Najma Kamali Jahan B.Ghasemi Ghodsi Mohammadi Ziarani Sahar moradian Alireza Badiei School of Chemistry College of ScienceUniversity of TehranTehranIran Department of Organic Chemistry Faculty of ChemistryAlzahra UniversityVanak SquareTehranIran

In this study, new nano spherical graphene modified with LDH(Layered Double Hydroxide) was prepared and used to remove As(Ⅲ) ion from aqueous solutions. At first, graphene oxide was synthesized from graphite using a well-known Hammer method. The obtained graphene oxide solution was sprayed in octanol solution under different temperatures and sprayed speed as influenced variables. The structure and physical characterization of synthesized spherical graphene oxide were determined by various techniques,including FT-IR, N_(2) adsorption–desorption, SEM, TEM, and EDX. In the next step, the hydrothermal method was applied to deposition LDH on the spherical graphene oxide. The synthesized spherical graphene modified by LDH was used to remove As(Ⅲ) as a toxic heavy metal ion. The effect of influenced variables including p H, contact time, amount of sorbent, and type eluent studied and the optimum values were as 8, 30, 50, and HCl(0.5 mol·L^(-1)), respectively. After optimization, the studied sorbent was shown a high adsorption capacity(149.3 mg·g^(-1)). The adsorption mechanism and kinetic models exhibited good agreement with the Langmuir isotherm and pseudo-second-order trends, respectively. Besides, the synthesized product was tested for seven times without significant loss in its sorption efficiency.

关键词： Graphene-based spherical adsorbent Layered double hydroxide(LDH) Adsorption Spray-assisted deep-frying

Climate change impacts on the streamflow of Zarrineh River,Iran

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Journal of Arid Land 2021年第9期13卷 891-904页

作者： Farhad YAZDANDOOST Sogol moradian Department of Civil Engineering K.N.Toosi University of TechnologyTehran 19697Iran

Zarrineh River is located in the northwest of Iran,providing more than 40%of the total inflow into the Lake Urmia that is one of the largest saltwater lakes on the *** Urmia is a highly endangered ecosystem on the brink of *** paper studied the impacts of climate change on the streamflow of Zarrineh *** streamflow was simulated and projected for the period 1992-2050 through seven CMIP5(coupled model intercomparison project phase 5)data series(namely,BCC-CSM1-1,BNU-ESM,CSIRO-Mk3-6-0,GFDL-ESM2G,IPSL-CM5A-LR,MIROC-ESM and MIROC-ESM-CHEM)under RCP2.6(RCP,representative concentration pathways)and *** model data series were statistically downscaled and bias corrected using an artificial neural network(ANN)technique and a Gamma based quantile mapping bias correction *** best model(CSIRO-Mk3-6-0)was chosen by the TOPSIS(technique for order of preference by similarity to ideal solution)method from seven CMIP5 models based on statistical *** simulation of streamflow,a rainfall-runoff model,the hydrologiska byrans vattenavdelning(HBV-Light)model,was *** on hydro-climatological changes in Zarrineh River basin showed that the mean daily precipitation is expected to decrease from 0.94 and 0.96 mm in 2015 to 0.65 and 0.68 mm in 2050 under RCP2.6 and RCP8.5,*** the case of temperature,the numbers change from 12.33℃ and 12.37℃ in 2015 to 14.28℃ and 14.32℃ in *** to these climate scenarios,this study projected a decrease of the annual streamflow of Zarrineh River by half from 2015 to 2050 as the results of climatic changes will lead to a decrease in the annual streamflow of Zarrineh River from 59.49 m^(3)/s in 2015 to 22.61 and 23.19 m^(3)/s in *** finding is of important meaning for water resources planning purposes,management programs and strategies of the Lake's endangered ecosystem.

关键词： climate change water resources management climate model intercomparison project phase5(CMIP5) artificial neural network(ANN) bias correction hydrologiska byrans vattenavdelning(HBV-Light) Zarrineh River