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Plant-pollinator metanetworks in fragmented landscapes:a simulation study

Ecological Processes 2023年第1期12卷 415-424页

作者： ehsan rahimi Chuleui Jung Agricultural Science and Technology Institute Andong National UniversityAndong City 36729Republic of Korea Department of Plant Medicals Andong National UniversityAndong CityRepublic of Korea

Background The topology of the plant-pollinator network can be explained by the species’abundance and their random ***-pollinator networks can be studied in the context of a landscape,because each patch can accommodate a certain local *** populations of pollinators in the landscape can be connected through migration and then constitute a metanetwork that is known as a combination of spatial and ecological *** this regard,habitat fragmentation can affect the topology of plant-pollinator metanetworks through changes in the species abundance and limiting their ***,it is not clear what pattern(fragmented or aggregated)of the landscape structure can accommodate networks with a higher degree of *** we created simulated landscapes with different forest proportions scenarios(from 5%to 50%of the total landscape)and degrees of ***,for each landscape,we limited the proportion of pollinators to the forest *** assumed that plants and pollinators are randomly distributed around the landscape and interact *** used landscape metrics to measure different aspects of landscape structure and bipartite metrics for calculating the degree of specialization in plant-pollinator *** The statistical relationship between bipartite and landscape metrics showed that the relationship between the topology of plant-pollinator networks and the landscape structure is affected by the forest amount in the landscape and the degree of forest *** also found that according to the nestedness and H2(a measure of specialization)metrics,fragmented landscapes contain more general plant-pollinator *** Our findings suggest that fragmented landscapes,characterized by scattered forest patches,can promote higher levels of interaction between limited pollinators and diverse flowers,leading to more general plant-pollinator networks.

关键词： Plant–pollinator metanetwork Habitat fragmentation Simulated landscape Landscape metrics Bipartite metrics

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Using the Lonsdorf model for estimating habitat loss and fragmentation effects on pollination service

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Ecological Processes 2021年第1期10卷 303-315页

作者： ehsan rahimi Shahindokht Barghjelveh Pinliang Dong Environmental Research Institute Shahid Beheshti UniversityTehranIran Department of Geography and the Environment University of North TexasDentonTexasUSA.

One of the most important issues related to landscape ecology and ecosystem services is finding the pattern of habitat patches that offers the highest pollination in agricultural *** this regard,two processes of habitat loss and fragmentation strongly affect the relationship between pollination and the pattern of habitat *** the present study,we aimed to examine the effects of habitat loss and fragmentation on pollination *** this purpose,first,we generated different simulated agricultural landscapes,including two habitats of forest and ***,according to the Lonsdorf model,we estimated the potential of the simulated landscapes in providing pollination in different ***,using statistical models,we estimated the effects of habitat loss and fragmentation on pollination at the landscape and farm *** results showed that the effects of habitat loss and fragmentation on pollination were completely different at the landscape and farm *** the landscape level,fragmentation negatively affected pollination,but at the farm level,the maximum pollination rate was observed in the landscapes with a high degree of *** the habitat loss effects,our results showed that pollination decreased linearly at the landscape level as habitat amount decreased,but at the farm level,it decreased *** present study considered the level of analysis(i.e.,landscape and farm levels)as a critical factor affecting pollination changes caused by *** showed that using the Lonsdorf model could lead to confusing results for the landscape ecologists and alert farmers who want to reduce the adverse effects of fragmentation on their products by creating new forest ***,agriculturalists and landscape ecologists should consider that the pollination rate at the landscape and farm levels is completely different according to the model and provide contradictory results about the process of habita

关键词： Landscape ecology Pollination service Habitat loss Fragmentation Landscape metrics Lonsdorf model

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Estimating landscape structure efects on pollination for management of agricultural landscapes

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Ecological Processes 2021年第1期10卷 817-828页

作者： ehsan rahimi Shahindokht Barghjelveh Pinliang Dong Environmental Sciences Research Institute Shahid Beheshti UniversityTehranIran. Department of Geography and the Environment University of North TexasDentonTXUSA

Background:The growing human population around the world is creating an increased demand for *** agricultural landscapes,forests are cleared and turned into agricultural land to produce more *** the productivity of agricultural land per unit area may prevent extreme forest *** many agricultural products are dependent on pollinators,it is possible to increase crop production by increasing the pollination rate in the agricultural *** are highly dependent on forest patches in agricultural ***,by creating new forest patches around agricultural felds,we can increase the pollination rate,and thus the crop *** this regard,estimating the efects of diferent scenarios of forest fragmentation helps us to fnd an optimized pattern of forest patches for increasing pollination in an agricultural ***:To investigate the efect of diferent forest fragmentation scenarios on pollination,we used simulated agricultural landscapes,including diferent forest proportions and degrees of *** landscape metrics,we estimated the relationship between pollination and landscape structure for each ***:Our results showed that for increasing pollination,two signifcant factors should be considered:habitat amount and capacity of small patches to supply *** found that when the capacity of small patches in supplying pollination was low,fragmented patterns of forest patches decreased *** increasing capacity,landscapes with a high degree of forest fragmentation showed the highest levels of *** was an exception for habitat amounts(the proportion of forest patches)less than 0.1 of the entire landscape where increasing edge density,aggregation,and the number of forest patches resulted in increasing pollination in all ***:This study encourages agriculturists and landscape planners to focus on increasing crop production per unit area by polli

关键词： Landscape ecology Pollination Landscape metrics Simulated landscapes Small forest patches

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A new method to determine the synergistic effects of area ratio and microstructure on the galvanic corrosion of LAS A508/309 L/308 L SS dissimilar metals weld

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Journal of Materials Science & Technology 2021年第19期78卷 38-50页

作者： Bright O.Okonkwo Hongliang Ming Jianqiu Wang En-Hou Han ehsan rahimi Ali Davoodi Saman Hosseinpour CAS Key Laboratory of Nuclear Materials and Safety Assessment Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China Materials and Metallurgical Engineering Department Faculty of EngineeringFerdowsi University of MashhadMashhad ***Iran Polytechnic Department of Engineering and Architecture University of Udine33100 UdineItaly John A.Paulson School of Engineering and Applied Sciences Harvard UniversityCambridgeMA 02138USA Institute of Particle Technology(LFC) Friedrich-Alexander-Universitdt-Erlangen-Numberg(FAU)91058 ErlangenGermany

The synergistic effects of area ratio and microstructure on the galvanic corrosion of A508/309 L/308 L dissimilar metals weld(DMW)are studied by a multi-analytical *** was demonstrated that decreasing the anode/cathode surface area ratio obviously enhances the corrosion rate of A508,both locally and *** analyses of the AFM results enabled quantitative comparison of the corrosion behaviour of the different surface *** was revealed that in the galvanic interaction of the DMW,the grain refined region corrodes most,followed by the partial grain refined region and base metal matrix of the A508,*** electrochemical localization index(LI)estimation method and AFM analysis both confirmed the presence of a mixed(localized and uniform)corrosion phenomenon occurring on the surface of the A508 anode metal in the galvanic interaction of the dissimilar ***,the degree of synergism equation was utilized to describe the synergistic effects of anode/cathode area ratio and the microstructure of the samples on the galvanic corrosion of LAS A508/309 L/308 L SS DMW.

关键词： Low alloy steel Stainless steel SEM AFM Galvanic corrosion Inclusion

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Distribution and tensile strength of Hornbeam （Carpinus betulus） roots growing on slopes of Caspian Forests, Iran

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Journal of Forestry Research 2009年第A2期20卷 105-110,I0001页

作者： ehsan Abdi Baris Majnounian Hassan rahimi Mahmud Zobeiri Department of Forestry University ofTehran Karaj 31585-3314 Iran Department of Irrigation University ofTehran Karaj 31585-3314 lran

Biomechanical characteristics of the root system of hornbeam （Carpinus betulus） were assessed by measuring Root Area Ratio （RAR） values and tensile strength of root specimens of eight hornbeam trees growing on hilly terrain of Northern Iran. RAR values of the roots were obtained using profile trenching method at soil depth of the top 0.1 m. In total 123 root specimens were analyzed for tensile strength. Results indicate that in general, RAR decreases with depth, following a power function. The RAR values in up and down slopes have no significant statistical differences. In most cases, the maximum RAR values were located in soil depth of the top 0.1 m, with maximum rooting depth at about 0.75 m. The minimum and maximum RAR values along the profiles were 0.004% and 6.431% for down slope and 0.004% and 3.995% for up slope, respectively. The number of roots in the up and down slope trenches was not significantly different. In the same manner as for RAR, number of roots distributing with depth was satisfactorily approximated a power function. The penetration depths of above 90 percent of the roots were at soil depths of 50 cm and 60 cm for up and down slopes, respectively. Results of Spearman＇s bivariate correlation showed no significant correlation between the RAR value with tree diameter and gradient of slope and number of roots. The mean value of root tensile strength was 31.51 ± 1.05 MPa and root tensile strength decreased with the increase in root diameter, following a power law equation. Using ANCOVA, we found intraspecies variation of tensile strength.

关键词： biomechanical Hornbeam Carpinus betulus root area ratio (RAR) root system root tensile strength.

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Optimized algorithm in mine production planning, mined material destination, and ultimate pit limit

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Journal of Central South University 2018年第6期25卷 1475-1488页

作者： rahimi ESMAEIL Moosavi ehsan Shirinabadi REZA Gholinejad MEHRAN Department of Mining Engineering Islamic Azad UniversitySouth Tehran BranchTehran 163963476Iran ~ Central South University Press and Springer-Verlag GmbH Germanypart of Springer Nature 2018

An integral connection exists among the mine production planning, the mined material destination, and the ultimate pit limit （UPL） in the mining engineering economy. This relation is reinforced by real information and the benefits it engenders in the mining economy. Hence, it is important to create optimizing algorithms to reduce the errors of economic calculations. In this work, a logical mathematical algorithm that considers the important designing parameters and the mining economy is proposed. This algorithm creates an optimizing repetitive process among different designing constituents and directs them into the maximum amount of the mine economical parameters. This process will produce the highest amount of ores and the highest degree of safety. The modeling produces a new relation between the concept of the cutoff grade, mine designing, and mine planning, and it provides the maximum benefit by calculating the destination of the ores. The proposed algorithm is evaluated in a real case study. The results show that the net present value of the mine production is increased by 3% compared to previous methods of production design and UPL.

关键词： mined material destination ultimate pit limit net present value production planning

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Cattle toxoplasmosis in Iran:a systematic review and meta-analysis

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Asian Pacific Journal of Tropical Medicine 2015年第2期8卷 120-126页

作者： Shahabeddin Sarvi Ahmad Daryani Mohammad Taghi rahimi Mohsen Aarabi Azar Shokri ehsan Ahmadpour Azadeh Mizani Mahdi Sharif Toxoplasmosis Research Center Mazandaran University of Medical SciencesSariIranPostal Code:48168-95475 Department of Parasitology and Mycology Sari Medical SchoolMazandaran University of Medical SciencesSariIranPostal Code:48168-95475 Sari Medical School Mazandaran University of Medical SciencesSariIranPostal Code:48168-95475

Objective:To analyze and review the overall seroprevalence rate of Toxoplasma gondii(***) infection in cattle from ***:In the current study,data collection(published and unpublished papers,abstracts of national scientific congresses and dissertations) using particular terms was carried out systematically on the following electronic databases like PubMed,Google Scholar,Ebsco,Science Direct,Scopus,Magiran,Irandoc,IranMedex and SID(Scientific Information Database).Results:A total of 22 studies since 1983 to 2012 reporting the seroprevalence of toxoplasmosis in cattle from different regions of Iran met our eligibility *** pooled proportion of toxoplasmosis,using random effect model,among cattle in Iran from over the 30-year period was estimated 18.1%(95%CI:9.9%to 28.2%).Conclusions:This study firstly establishes a crude seroprevalence rate of Toxoplasma infection in cattle which can lead us to understand the condition of eattle toxoplasmosis,which have to take into accounted fur an appropriate and effective prevention and ***,it compares and discusses elaborately the role of risk factors including sex,age and breed in the epidemiology of the ***,it determines gaps and drawbacks in the prior studies which are greatly useful to design more accurate investigations in the future.

关键词： Toxoplasma gondii Prevalence Systematic review Meta-analysis Iran

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Application of diffusive transport model for better insight into retardation mechanisms involved in ion-imprinted membrane transport

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Chinese Journal of Chemical Engineering 2016年第9期24卷 1161-1165页

作者： ehsan Salehi Department of Chemical Engineering Faculty of Engineering Arak University

Heavy metal removal from water is a great concern for environmentalists and engineers. Ion-imprinted membranes are among the state of the art technologies for selective adsorption of heavy metals from aqueous environment. Dialysis permeation of nickel ions through Ni(II)-imprinted membranes has been thermodynamically studied in our prior work. In current study, the diffusive transport model was developed and then applied for better insight into the retardation mechanisms involved in the ion-imprinted membrane transport. The Sips isotherm model was coupled with the transport model to obtain the governing equation. Chemisorption and physical interactions(bulk diffusion and pore-clogging) were the most probable retardation mechanisms according to the modeling results. Relative retardation factor(η) was also defined as; transport-rate controlled by chemical adsorption to that controlled by physical interactions. With the help of the retardation factor, it was understood that the membrane behavior gradually changes from chemisorption to facilitated transport during permeation time. Effect of important operating parameters such as time, temperature and concentration on transport behavior was also investigated. Results indicated that chemisorption rate is rather higher at lower concentrations, early permeation times and reduced temperatures. In addition, η tabulated greater values for Ni(II) compared to Co(II) due to the imprinting effect.

关键词： Ion-imprinted membrane Mathematical modeling Chemisorption Retardation mechanism

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Effects of modified graphene oxide(GO) nanofluid on wettability and IFT changes: Experimental study for EOR applications

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Petroleum Science 2022年第4期19卷 1779-1792页

作者： ehsan Jafarbeigi Farhad Salimi ehsan Kamari Mohsen Mansouri Department of Chemical Engineering Kermanshah BranchIslamic Azad UniversityKermanshahIran Department of Petroleum Engineering Research Institute of Petroleum IndustryTehranIran Department of Chemical Engineering llam UniversityllamIran

The application of nanoparticles(NPs) in enhanced oil recovery(EOR) offers a practical approach to resolving some surface-related problems encountered in contemporary technological processes. In this study, graphene oxide nanosheets(GONs) were synthesized by Hummer's method and, then, were subjected to surface modification by hexamethyldisilazane(HMDS) and diazonium sulfonic(DS) compounds. The new combination was known as GO-Su-HMDS. The potential stability of GO-Su-HMDS nanofluids(NFs) was investigated using the zeta(ζ) potential test. A comparative study of the effect of the synthesized NFs on wettability alteration of the reservoir rock was performed using interfacial tension(IFT) and contact angle experiments. According to the results of this study, the contact angle decreased from the initial value of 161.(oil wet) to 35.(water wet). In addition, IFT decreased from18.45 mN/m for deionized(DI) water to 8.8 mN/m for 500 ppm GO-Su-HMDS NF. Moreover, the results of flooding experiments showed that the NPs of a GO-Su-HMDS concentration of 400 and 500 ppm could increase the oil recovery by 20% and 19%, respectively. The experimental results showed that GO-SuHMDS NFs with a concentration of 500 ppm have the best efficiency in terms of altering the wettability of the rock from oil wet to water wet. Thus, it can be said that this nanofluid can reduce the contact angle and IFT and also increase the sweeping efficiency of oil.

关键词： Wettability alteration Graphene oxide Contact angle Interfacial tension Zeta potential

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Discrete element modeling of inherently anisotropic granular assemblies with polygonal particles

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Particuology 2012年第5期10卷 542-552页

作者： ehsan Seyedi Hosseininia Civil Engineering Department Faculty of Engineering Ferdowsi University of MashhadMashhad Iran

In the present article, we study the effect of inherent anisotropy, i.e., initial bedding angle of particles and associated voids on macroscopic mechanical behavior of granular materials, by numerical simulation of several biaxial compression tests using the discrete element method （DEM）. Particle shape is considered to be irregular convex-polygonal. The effect of inherent anisotropy is investigated by following the evolution of mobilized shear strength and volume change during loading. As experimental tests have already shown, numerical simulations also indicate that initial anisotropic condition has a great influence on the strength and deformational behavior of granular assemblies. Comparison of simulations with tests using oval particles, shows that angularity influences both the mobilized shear strength and the volume change regime, which originates from the interlocking resistance between particles.

关键词： Inherent anisotropyGranular materialDiscrete element methodPolygonal particles

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