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Joint simulation of cross-correlated ore grades and geological domains:an application to mineral resource modeling

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Frontiers of Earth Science 2023年第2期17卷 417-436页

作者： Nasser MADANI mohammad maleki School of Mining and Geosciences Nazarbayev UniversityAstana 010000Kazakhstan Department of Metallurgical and Mining Engineering Universidad Católica del NorteAntofagasta 1270709Chile

Spatial modeling of ore grades is frequently impacted by the local variation in geological domains such as lithological characteristics,rock types,and geological *** this information may lead to biased results in the final ore grade block model,subsequently impacting the downstream processes in a mining chain *** the current practice of ore body evaluation,which is known as stochastic cascade/hierarchical geostatistical modeling,the geological domain is first characterized,and then,within the geological model,the ore grades of interest are *** practice may be unrealistic in the case when the variability in ore grade across the boundary is gradual,following a smooth *** reproduce such characteristics,the cross dependence that exists between the ore grade and geological formations is considered in the conventional joint simulation between continuous and categorical ***,when using this approach,only one ore variable is considered,and its relationship with other ore grades that may be available at the sample location is *** this study,an alternative approach to jointly model two cross-correlated ore grades and one categorical variable(i.e.,geological domains)with soft contact relationships that exist among the geological domains is *** statistical and geostatistical tools are provided for variogram inference,Gibbs sampling,and conditional *** algorithm is also tested by applying it to a Cu deposit,where the geological formations are managed by the local and spatial distribution of two cross-correlated ore grades,Cu and Au,throughout the *** results show that the proposed algorithm outperforms other geostatistical techniques in terms of global and local reproduction of statistical parameters.

关键词： geostatistical simulation categorical variable continuous variable geological domain variogram inference

Regularity classification and corresponding analysis method requirements of horizontally curved bridges with unequal pier heights

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Earthquake Engineering and Engineering Vibration 2023年第2期22卷 549-571页

作者： mohammad Jalal maleki-amin Shahrokh Maalek School of Civil Engineering Tehran UniversityTehran 11155-4563Iran Iranian Bridge Engineering Association Tehran 36481684Iran

The seismic behavior of horizontally curved bridges,particularly with unequal height piers,is more complicated than that of straight bridges due to their geometric *** this study,the seismic responses of several horizontally curved single-column-bent viaducts with various degrees of curvature and different pier heights have been investigated,employing three different analysis approaches:namely,modal pushover analysis,uniform load method,and nonlinear time history *** the investigated bridge configurations and utilizing the most common regularity indices,the results indicate that viaducts with 45-degree and 90-degree deck subtended angles can be categorized as regular and moderately irregular,respectively,while the bridges with 180-degree deck subtended angle are found to be highly ***,the viaducts whose pier heights are asymmetric may be considered as irregular for almost all ranges of the deck subtended *** effects of higher transverse and longitudinal modes are discussed and the minimum analysis requirements are identified to assess the seismic response of such bridge configurations for design *** the Regularity Indices used here are useful tools to distinguish between regular and irregular bridges,further studies are needed to improve their reliability.

关键词： horizontally curved bridges unequal height piers pushover analysis regularity index seismic analysis and response

Healthcare utilization patterns and economic burden of animal bites:A cross-sectional study

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Journal of Acute Disease 2021年第4期10卷 142-146页

作者： Vahid Bay Aziz Rezapour Mehdi Jafari mohammad Reza maleki Irvan Masoudi Asl Department of Healthcare Services Management School of Health Management&Information SciencesIran University of Medical SciencesTehranIran Infectious Diseases Research Centre Golestan University of Medical SciencesGorganGolestanIran Health Management and Economics Research Center Health Management Research InstituteIran University of Medical SciencesTehranIran

Objective:To determine the healthcare utilization patterns and estimate the economic burden of animal bites in Golestan province,north part of ***:This cross-sectional study was performed based on the data of 12181 animal-bite patients from Golestan province who were referred to the rabies prophylaxis centers between March 2019 and March *** study was a societal perspective,and all patients were investigated by census *** micro-costing method with a bottom-up approach as well as the human capital approach were used to estimate the economic ***:In our study,the economic burden caused by animal bites was estimated at$1383639(275354672060 Rials).The largest share of costs was related to direct healthcare costs,direct non-healthcare costs,and indirect costs accouting for 91%,5%,and 4%,*** addition,the average cost of a animal-bite patient was estimated at$113.5(22605260 Rials)(The average cost of a case in type 2 and 3 exposures was$45 and$412.8,respectively).The largest share of direct healthcare costs was related to immunoglobulin,vaccine,and personnel expenses accounting for 61.3%,19.8%,and 11.65%,***:Our study shows that animal bites in Golestan province,north of Iran impose a high economic burden on the communities,especially the healthcare system,which indicates the need to review management and control programs of animal bites and rabies based on animal-bite patterns of the area.

关键词： Animal bites Rabies Economic burden

Transesterification of canola oil over Li/Ca-La mixed oxide catalyst:Kinetics and calcination temperature investigations

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燃料化学学报 2017年第4期45卷 442-448页

作者： Hesam maleki mohammad Kazemeini Department of Chemical and Petroleum Engineering Sharif University of Technology

In this research,a solid 1%Li/Ca-La mixed oxide catalyst was prepared using co-precipitation method followed by wet *** prepared catalyst was used in the transesterification reaction of canola oil and methanol for biodiesel *** effects of calcination and reaction temperatures were investigated on the activity of the *** addition,rate of the reaction was studied through a kinetic model for which parameters were *** properties and structure of the catalyst were characterized through the powder X-ray diffraction(XRD),thermogravimetry/derivative thermogravimetry(TG/DTG),and Fourier transform infrared spectroscopy *** these emphasized that the performance of the catalyst corresponded to the generation of the active sites and their thermal activation.

关键词：油共炼基团相对含量固体残渣干基无灰转化率

Micromechanical simulation and experimental investigation of aluminum-based nanocomposites

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Defence Technology（防务技术） 2021年第1期17卷 196-201页

作者： mohammad Javad Ghasemi mohammad Silani Ali maleki Mostafa Jamshidian Department of Mechanical Engineering Isfahan University of TechnologyIsfahan84156-83111Iran

Ceramic reinforced metal matrix nanocomposites are widely used in aerospace and auto industries due to their enhanced mechanical and physical *** this research,we investigate the mechanical properties of aluminum/Nano-silica composites through experiments and ***/Nanosilica composite samples with different weight percentages of silica nanoparticles are prepared via powder *** this method,Nano-silica and aluminum powders are mixed and compressed in a mold,followed by sintering at high *** tensile testing of the nanocomposite samples shows that adding one percent of Nano-silica causes a considerable increase in mechanical properties of nanocomposite compared to pure aluminum.A computational micromechanical model,based on a representative volume element of aluminum/silica nanocomposite,is developed in a commercial finite element *** model employs an elastoplastic material model along with a ductile damage model for aluminum matrix and linear elastic model for nano-silica *** careful determination of model parameters from the experimental results of pure aluminum samples prepared by powder metallurgy,the proposed computational model has shown satisfactory agreement with *** validated computational model can be used to perform a parametric study to optimize the microstructure of nanocomposite for enhanced mechanical properties.

关键词： Aluminum/nano-silica composites Powder metallurgy Micromechanics

Risk factors for congenital nasolacrimal duct obstruction in children under two years of age

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国际眼科杂志 2025年第1期25卷 17-23页

作者： Rozhin Kasiri Gholamreza Khataminia Ali Kasiri mohammad Sadegh Mirdehghan mohammad Armin Kasiri Infectious Ophthalmologic Research Center Ahvaz Jundishapur University of Medical SciencesAhvaz ***Iran Islamic Azad University Tehran Medical Sciences Tehran ***Iran

·AIM:To identify various risk factors that may play a significant role in the development of congenital nasolacrimal duct obstruction(CNLDO).·METHODS:This observational case-control study included a case group of 122 children less than two years of age with CNLDO who underwent probing and irrigation treatment at the ophthalmology department of Imam Khomeini Hospital in Ahvaz,Iran,from June 2022 to June2024.A control group of 122 age-matched children without CNLDO was also included for *** was collected from the children's medical records.·RESULTS:The study found a significant correlation between the occurrence of CNLDO and several maternal factors,such as preeclampsia,the use of levothyroxine,hypothyroidism,having more than three pregnancies(gravidity>3),natural pregnancy,and gestational diabetes ***,in children,factors,such as oxygen therapy,anemia,reflux,jaundice,and a family history of CNLDO in first-degree relatives were associated with CNLDO,and maternal preeclampsia and hypothyroidism were found to significantly increase the risk of developing CNLDO in children.·CONCLUSION:Given that CNLDO affects both premature and full-term children,the present findings may potentially facilitate the early identification of children and infants at risk of nasolacrimal duct obstruction,thereby preventing the onset of chronic dacryocystitis.

关键词： risk factors congenital nasolacrimal duct obstruction children

Investigating the influence of delamination on the stiffness of composite pipes under compressive transverse loading using cohesive zone method

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Frontiers of Structural and Civil Engineering 2019年第6期13卷 1316-1323页

作者： Sattar maleki Roham RAFIEE Abolfazl HASANNIA mohammad Reza HABIBAGAHI Department of Mechanical Engineering Faculty of EngineeringQuchan University of TechnologyQuchan 94771-67335Iran Composites Research Laboratory Faculty of New Sciences and TechnologiesUniversity of TehranTehran ***Iran

The effect of delamination on the stiffness reduction of composite pipes is studied in this *** stiffness test of filament wound composite pipes is simulated using cohesive zone *** modeling is accomplished to study the effect of the geometrical parameters including delamination size and its position with respect to loading direction on stiffness of the composite *** first,finite element results for stiffness test of a perfect pipe without delamination are validated with the experimental results according to ASTM *** is seen that the finite element results agree well with experimental *** the finite element model is developed for composite pips with delaminated areas with different primary ***,the effect of the size of delaminated region on longitudinal and tangential directions and also its orientation with respect to loading direction on delamination propagation and stiffness reduction of the pipes is assessed.

关键词： delamination composite pipes stiffness test cohesive zone method

Failure criterion effect on solid production prediction and selection of completion solution

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Journal of Rock Mechanics and Geotechnical Engineering 2017年第6期9卷 1123-1130页

作者： Dariush Javani Bernt Aadnoy Mahdi Rastegarnia Siavash Nadimi mohammad Ali Aghighi Bijan maleki Department of Mining Engineering Imam Khomeini International UniversityQazvinIran Department of Petroleum Engineering University of StavangerStavangerNorway Department of Petrophysics Homai Well Services CompanyTehranIran Department of Chemical Engineering Energy and Geoscience InstituteThe University of UtahSalt Lake CityUT 84112USA Department of Mining Engineering University of TehranTehranIran

Production of fines together with reservoir fluid is called solid production. It varies from a few grams or less per ton of reservoir fluid posing only minor problems, to catastrophic amount possibly leading to erosion and complete filling of the borehole. This paper assesses solid production potential in a carbonate gas reservoir located in the south of Iran. Petrophysical logs obtained from the vertical well were employed to construct mechanical earth model. Then, two failure criteria, i.e. Mohre Coulomb and Mogi-Coulomb,were used to investigate the potential of solid production of the well in the initial and depleted conditions of the reservoir. Using these two criteria, we estimated critical collapse pressure and compared them to the reservoir pressure. Solid production occurs if collapse pressure is greater than pore pressure. Results indicate that the two failure criteria show different estimations of solid production potential of the studied reservoir. Mohre Coulomb failure criterion estimated solid production in both initial and depleted conditions, where Mogi-Coulomb criterion predicted no solid production in the initial condition of reservoir. Based on Mogi-Coulomb criterion, the well may not require completion solutions like perforated liner, until at least 60% of reservoir pressure was depleted which leads to decrease in operation cost and time.

关键词： Solid production Mechanical earth model Failure criterion Reservoir depletion Completion solution

In vitro and in vivo susceptibility of Leishmania major to some medicinal plants

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Asian Pacific Journal of Tropical Biomedicine 2017年第1期7卷 37-42页

作者： Fatemeh maleki Mitra Zarebavani Mehdi Mohebali mohammad Saaid Dayer Fateme Hajialiani Fatemeh Tabatabaie Faculty of Para Medical Sciences Iran University of Medical SciencesTehranIran Allied Medical Sciences Medical Laboratory SciencesTehran University of Medical SciencesTehranIran Center for Research of Endemic Parasites of Iran(CREPI) Tehran University of Medical SciencesTehranIran Department of Parasitology and Medical Entomology Faculty of Medical SciencesTarbiat Modares UniversityTehranIran Department of Parasitology and Mycology Faculty of MedicineIran University of Medical SciencesTehranIran

Objective: To evaluate the efficacy of some medicinal plants and systemic glucantime in a comparative manner against the causative agent of cutaneous leishmaniasis both in vitro and in BALB/c ***: For in vivo testing, inbred mice were challenged with Leishmania major parasites and the resultant ulcers were treated with extract based-ointments applied topically two times per day for a period of 20 days. A group of 56 mice were randomly divided into 7 subgroups. The control group received the ointment void of extracts,whereas the reference group received glucantime only. The efficacy of treatments was evaluated by measuring ulcer diameter, parasite burden and NO ***: Our results indicated that plant extract based-ointments were effective in reducing ulcer size and parasite burden in spleens, but their effects did not differ significantly from that of glucantime. The plant extracts tested in this study were able to increase NO production that helped parasite ***: Our findings indicate that the tested plant extracts are effective against Leishmania major both during in vitro and in vivo experiments, but further researches are required to recommend a potential plant extract as an alternative drug.

关键词： Leishmaniasis Glucantime Plant extracts Mice Medicinal plants