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The Lanthanide Tetrad Effect in Argillic Alteration: An Example from the Jizvan District, Northern Iran

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Acta Geologica Sinica(English Edition) 2018年第4期92卷 1468-1485页

作者： ali ABEDINI Mansour REZAEI AZIZI ali asghar calagari Department of Geology Faculty of Sciences Urmia University Department of Earth Sciences Faculty of Natural Sciences University of Tabriz

Intrusion of quartz-monzodioritic igneous bodies of Oligocene age into Eocene lithic crystal tufts and trachy-basalts resulted in the occurrence of a widespread argillic alteration zone in the Jizvan district （northern Iran）. Mineralogically, the argillie alteration zone includes minerals such as kaolinite, quartz, smectite, pyrophyllite, muscovite-illite, alunite, rutile, calcite, feldspar, chlorite, hematite and goethite. Therefore, the non-CHARAC behaviour for trace elements in the argillic samples is reflected in the non-chondritic Y/Ho and Zr/Hf ratios and the irregular REE patterns, which appear related to the tetrad effect phenomenon. The chondrite-normalized REE distribution patterns indicate both concave （W-shaped） and convex （M-shaped） tetrad effects in the argillic samples. Based on the field evidence and the results from geochemical studies, it can be concluded that the samples from the argillic alteration zone having high fourth tetrad effect values （〉0.30） were developed in the fault and breccia zones. The results indicate that factors such as preferential scavenging by Mn-oxides, crystallization of clay minerals, fluid-rock interaction, overprint of hypogene mineral assemblage by supergene ones, and the structural control, have all played an important role in the occurrence of tetrad effects in samples of the argillic zone in the Jizvan district.

关键词： REE geochemistry tetrad effect argillic alteration Jizvan Iran

REE Tetrad Effect as a Powerful Indicator of Formation Conditions of Karst Bauxites: A Case Study of the Shahindezh Deposit, NW Iran

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Acta Geologica Sinica(English Edition) 2019年第4期93卷 912-927页

作者： ali ABEDINI Mansour REZAEI AZIZI ali asghar calagari Department of Geology Faculty of SciencesUrmia University*** UrmiaIran Department of Earth Sciences Faculty of Natural SciencesUniversity of Tabriz*** TabrizIran

Study of the concentration of major,trace,and rare earth elements(REE)in the Shahindezh karst bauxite deposit,northwestern Iran clarifies the relationship of the tetrad effect with geochemical parameters in the bauxite *** existence of irregular curves in the chondrite-normalized REE patterns as well as non-CHARAC behavior of geochemically isovalent pairs(Y/Ho)are related to the tetrad *** meaningful positive correlation between the sizes of the calculated T3 tetrad effect and some geochemical factors such as Y/Ho,ΣREE,La/Y,(La/Yb)N,and(LREE/HREE)N as well as some major oxides-based parameters like Al2O3+LOI/SiO2+Fe2O3,Al2O3/Fe2O3,Al2O3+LOI,IOL,and SiO2+Fe2O3indicate that the studied bauxite horizon was likely deposited by different(acidic and/or alkalic)solutions at different *** lower part of the studied horizon with a thickness of^4.7 m displays alkali characteristics whereas the upper parts of the horizon with a thickness of^5.3 m are characterized by more acidic *** results are fully supported by the co-occurrence of convex-concave tetrad effect curves in the chondrite-normalized REE ***,the tetrad effect phenomenon used in this study has proved to be a good and reliable geochemical proxy to assess the conditions of the depositional environment in the Shahindezh bauxite ores.

关键词： Geochemistry REE Tetrad effect Karst bauxite Shahindezh Iran

A Preliminary Study on the Aghbolaq(Fe,Cu)Skarn Deposit,Oshnavieh,NW Iran:Constraints on Metasomatic Fluid Evolution

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Acta Geologica Sinica(English Edition) 2021年第3期95卷 846-859页

作者： Kamal SIAHCHESHM Nasrin KHAJEMOHAMMADLO ali asghar calagari ali ABEDINI Department of Earth Sciences University of TabrizTabriz ***Iran Geology Department Faculty of SciencesUrmia UniversityUrmia 57153Iran

The Aghbolaq skarn deposit is located in the Urumieh-Golpayegan plutonic belt,NW *** garnetite skarn(stageⅠ)has been intensely cross-cut by the magnetite-garnet skarn(stageⅡ)which were,in turn,cut and offset by the ore-hosting quartz veins/veinlets(stageⅢ).The predominance of andradite(Adr82.5–89.1)and its high Fe3+/Al ratio(up to 1685)apparently supports the high fO2,salinity and prevalence of magmatic/hydrothermal fluids involved,rather than meteoric waters,during the magnetite-garnet skarn *** major groups of fluid inclusions,namely aqueous(LV,LVS)and aqueous–carbonic(LVC,LLCVC),were recognized in garnet and quartz veins that,especially in growth zones and along intra-granular trails,better display fluid inclusion assemblages(FIAs)than those in *** prograde magnetite-garnet skarn was formed by the metasomatic fluid at relatively high Th(209–374℃),under a lithostatic pressure of~200 *** retrograde mineralized quartz veins were formed at temperatures ranging from 124℃to 256℃,by dilute and less saline(2.57–11.93 wt%NaCl eq.)hydrothermal fluids under a hydrostatic pressure of~80 *** fluid evolution of the Aghbolaq skarn began with an earlier simple cooling of metasomatic fluid during the prograde stage,followed by the later influx of low salinity meteoric fluids during the retrograde stage.

关键词： garnetite skarn mineral chemistry fluid inclusion ore fluid evolution Oshnavieh Iran

Transport mechanism in chemically reactive hybrid nanofluid flow containing gyrotactic micro-organisms over a curved oscillatory surface

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Applied Mathematics and Mechanics(English Edition) 2025年第1期46卷 177-192页

作者： M.NAVEED M.IMRAN T.asghar Z.ABBAS Department of Mathematics Division of Science and TechnologyUniversity of Education Department of Mathematics The Islamia University of Bahawalpur

This paper examines the transport analysis, including both heat transfer and mass transfer, in hybrid nanofluid flow containing gyrotactic microorganisms towards a curved oscillatory surface. The influence of magnetic fields is also inspected in terms of their physical characteristics. To depict the phenomena of transport, modified versions of both Fick's and Fourier's laws are used. Additionally, the characteristics of both heterogeneous and homogeneous chemical reactions are also incorporated. Utilizing a curvilinear coordinate system, the flow problem is formulated as partial differential equations(PDEs)for momentum, concentration, microorganism field, and energy. An analytical solution to the obtained flow equations is achieved utilizing the homotopy analysis method(HAM).The effects of significant flow parameters on the pressure and microorganism fields, velocity, oscillation velocity, concentration, and temperature distributions are shown via graphs. Furthermore, the variations in skin friction, mass transfer rate, heat transfer rate, and local motile number due to different involved parameters are presented in tables and are analyzed in detail. Graphical results indicate that the curves of velocity and temperature fields are enhanced as the values of the solid volume fraction variables *** is also verified that the concentration rate field decreases as the values of the homogeneous reaction strength parameter and the radius of curvature parameter increase, and it increases with the Schmidt number and the heterogeneous reaction strength *** outcomes show a favorable response of the motile number to advanced values of the Peclet number, the Schmidt number, the microorganism difference parameter, and the bio-convective Lewis number.

关键词： Peclet number

Resolving the Routine Presence of Kyanite, Andalusite and Sillimanite across a Region using Foliation Intersection/Inflection Axes Preserved in Porphyroblasts, Petrographic Observations and Thermobarometry

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Acta Geologica Sinica(English Edition) 2012年第5期86卷 1241-1250页

作者： asghar ali School of Earth and Environmental Science James Cook University Townsville Queensland 4811 Australia Department of Geology University of Peshawar Peshawar Khyber Pakhtunkhwa 25120 Pakistan

Constraints from P-T pseudosections （MnNCKFMASH system）, foliation intersection/ inflection axes preserved in porphyroblasts （FIAs）, mineral assemblages and textural relationships for rocks containing all three Al2 SiO5 polymorphs indicate a kyanite→ andalusite→ sillimanite sequential formation at different times rather than stable coexistence at the Al2SiO5 triple point. All three Al2SiO5 polymorphs grew in the Chl, Bt, Ms, Grt, St, Pl and Crd bearing Ordovician Clayhole Schist in Balcooma, northeastern Australia separately along a looped P-T-t-D path that swaps from clockwise to anticlockwise in the tectono-metamorphic history of the region. Kyanite grew during crustal thickening in an Early Silurian Orogenic event followed by decompression/heating, andalusite and fibrolitic sillimanite growth during Early Devonian exhumation.

关键词： Al2SiO5 triple point microtextures foliation intersection/inflection axes Barrovian sequence episodic porphyroblast growth

A discrete element model for simulating saturated granular soil

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Particuology 2011年第6期9卷 650-658页

作者： ali asghar Mirghasemi School of Civil Engineering College of Engineering University of Tehran

A numerical model is developed to simulate saturated granular soil, based on the discrete element method. Soil particles are represented by Lagrangian discrete elements, and pore fluid, by appropriate discrete elements which represent alternately Lagrangian mass of water and Eulerian volume of space. Macroscale behavior of the model is verified by simulating undrained biaxial compression tests. Micro-scale behavior is compared to previous literature through pore pressure pattern visualization during shear tests. It is demonstrated that dynamic pore pressure patterns are generated by superposed stress waves. These pore-pressure patterns travel much faster than average drainage rate of the pore fluid and may initiate soil fabric change, ultimately leading to liquefaction in loose sands. Thus, this work demonstrates a tool to roughly link dvnamic stress wave patterns to initiation of liQuefaction nhenomena.

关键词： Discrete element method Granular soil Saturated soil Pore pressure

Energy Efficiency in ARQ-Based Multi-Hop Systems and the Tradeoff with Throughput

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China Communications 2023年第6期20卷 60-71页

作者： ali asghar Haghighi Electrical and Computer Engineering Group Golpayegan College of EngineeringIsfahan University of TechnologyGolpayegan 87717-67498Iran

The minimum energy per bit(EPB)as the energy efficiency(EE)metric in an automatic retransmission request(ARQ)based multi-hop system is analyzed under power and throughput *** ARQ protocols including type-I(ARQ-I)and repetition redundancy(ARQ-RR)are considered and expressions for the optimal power allocation(PA)are *** the obtained optimal powers,the EE-throughput tradeoff(EETT)is analyzed and the EETT closed-form expressions for both ARQ protocols and in arbitrary average channel gain values are *** is shown that how different throughput requirements,especially the high levels,affect the EE ***,asymptotic analysis is made in the feasible high throughput values and lower and upper EETT bounds are derived for ARQ-I *** evaluate the EE a distributed PA scenario,as a benchmark,is presented and the energy savinggain obtained from the optimal PA in comparison with the distributed PA for ARQ-I and ARQ-RR protocols is discussed in different throughput values and node locations.

关键词： ARQ cooperative relaying energy efficiency green communication multi-hop systems routing algorithms throughput analysis

Particle shape consideration in numerical simulation of assemblies of irregularly shaped particles

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Particuology 2011年第4期9卷 387-397页

作者： Saba Abedi ali asghar Mirghasemi School of Civil Engineering College of Engineering University of Tehran

The mechanical behavior of granular materials depends much on the shape of the constituent particles. Therefore appropriate modeling of particle, or grain, shape is quite important. This study employed the method of direct modeling of grain shape （Matsushima ＆ Saomto, 2002）, in which, the real shape of a grain is modeled by combining arbitrary number of overlapping circular elements which are connected to each other in a rigid way. Then, accordingly, a discrete-element program is used to simulate the assembly of grains. In order to measure the effects of grain shape on mechanical properties of assembly of grains, three types of grains-high angular grains, medium angular grains and round grains are considered where several biaxial tests are conducted on assemblies with different grain types, The results show that the angularity of grains greatly affects the behavior of granular soil.

关键词： Discrete element method Granular soil Angularity Confining pressure

Survey on Video Security:Examining Threats,Challenges,and Future Trends

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Computers, Materials & Continua 2024年第9期80卷 3591-3635页

作者： ali asghar Amna Shifa Mamoona Naveed asghar Department of Artificial Intelligence Faculty of ComputingThe Islamia University of BahawalpurBahawalpur63100Pakistan School of Computer Science College of Science and EngineeringUniversity of GalwayGalwayH91 TK33Ireland

Videos represent the most prevailing form of digital media for communication,information dissemination,and ***,theirwidespread use has increased the risks of unauthorised access andmanipulation,posing significant *** response,various protection approaches have been developed to secure,authenticate,and ensure the integrity of digital *** study provides a comprehensive survey of the challenges associated with maintaining the confidentiality,integrity,and availability of video content,and examining how it can be *** then investigates current developments in the field of video security by exploring two critical research ***,it examine the techniques used by adversaries to compromise video data and evaluate their *** these attack methodologies is crucial for developing effective defense ***,it explores the various security approaches that can be employed to protect video data,enhancing its transparency,integrity,and *** compares the effectiveness of these approaches across different use cases,including surveillance,video on demand(VoD),and medical videos related to disease ***,it identifies potential research opportunities to enhance video data protection in response to the evolving threat *** this investigation,this study aims to contribute to the ongoing efforts in securing video data,providing insights that are vital for researchers,practitioners,and policymakers dedicated to enhancing the safety and reliability of video content in our digital world.

关键词： Attacks threats security services video manipulation video security