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Efficient nonenzymatic hydrogen peroxide sensor in acidic media based on Prussian blue nanoparticles-modified poly(o-phenylenediamine)/glassy carbon electrode

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Chinese Chemical Letters 2016年第3期27卷 481-486页

作者： Reza Ojani parisa Hamidi Jahan-Bakhsh Raoof Electroanalytical Chemistry Research Laboratory Faculty of ChemistryUniversity of Mazandaran

The Prussian blue nanoparticles（PBNPs） were prepared by a self-assembly process, on a glassy carbon（GC） electrode modified with a poly（o-phenylenediamine）（Po PD） film. The stepwise fabrication process of PBNPs-modified Po PD/GCE was characterized by scanning electron microscopy（SEM） and electrochemical impedance spectroscopy. The prepared PBNPs showed an average size of 70 nm and a homogeneous distribution on the surface of modified electrodes. The PBNPs/Po PD/GCE showed adequate mechanical, electrochemical stability and good sensitivity in comparison with other PB based H2O2 sensors. The present modified electrode exhibited a linear response for H2O2 reduction over the concentration range of 1–58.22 mmol L ^-1with a detection limit of ca. 0.8 mmol L ^-1（S/N = 3）, and sensitivity of 3187.89 m A（mol L ^-1） ^-1cm ^-2using the amperometric method. This sensor was employed for the H2O2 determination in real sample and also exhibited good interference resistance and selectivity.

关键词： Self-assembly Prussian blue nanoparticles Hydrogen peroxide Sensor

The effect of relative surface roughness on scour dimensions at the edge of horizontal apron

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International Journal of Sediment Research 2016年第2期31卷 159-163页

作者： parisa Koochak Mahmood Shafai Bajestan Shahid Chamran University College of Water Science Engineering

Roughened horizontal aprons are bed covering scour countermeasures constructed downstream of stilling basins and other places where scour hole may *** these cases scour occurs at the edge of the apron which can lead to failure of the *** the present study,24 experimental tests were carried out on four different aprons with(2,5,10 and 14.28 mm) roughness heights and two different bed material sizes of 0.8 and 1.4 mm under different flow *** results indicated that as the roughness height of apron increases,a significant reduction in the scour depth occurs.

关键词： Horizontal apron Bed roughness Scour Rivers

Synergistic effect of adsorption and photocatalytic degradation of oilfield-produced water by electrospun photocatalytic fibers of Polystyrene/Nanorod-Graphitic carbon nitride

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Journal of Environmental Sciences 2024年第7期141卷 287-303页

作者： parisa Azmoon Mehrdad Farhadian Alireza Pendashteh Amir H.Navarchian Department of Chemical Engineering Faculty of EngineeringUniversity of IsfahanIsfahanIran Department of Chemical Engineering Faculty of EngineeringUniversity of GuilanRashtIran Department of Water and Environmental Engineering Caspian Sea Basin Research CenterUniversity of GuilanRashtIran

Graphitic carbon nitride with nanorod structure(Nr-GCN)was synthesized using melamine as a precursor without any other reagents by hydrothermal pretreatment ***,FTIR,SEM,N_(2)adsorption-desorption from BET,UV-Vis DRS spectroscopy,and photoluminescence were used to characterize the prepared ***,the photoelectrochemical behavior of nanoparticles was studied by photocurrent transient response and cyclic voltammetry ***(PS)fibrous mat was fabricated by electrospinning technique and used as a support for the stabilization of the *** performance of the synthesized nanoparticles and photocatalytic fibers(PS/Nr-GCN)was evaluated in oilfield-produced water treatment under visible light *** this process,oil contaminants were adsorbed by hydrophobic polystyrene fibers and simultaneously degraded by *** removal efficiency of chemical oxygen demand(COD)has been obtained 96.6%and 98.4%by Nr-GCN and PS/Nr-GCN,respectively,at the optimum conditions of pH4,photocatalyst dosage 0.5 g/L,COD initial concentration 550 mg/L,and illumination time 150 *** gas chromatography-mass spectroscopy analysis results showed 99.3%removal of total petroleum hydrocarbons using photocatalytic fibers of PS/*** results demonstrated that the GCN has outstanding features like controllable morphology,visible-light-driven,and showing high potential in oily wastewater ***,the synergistic effect of adsorption and photocatalytic degradation is an effective technique in oilfield-produced water treatment.

关键词： Graphitic carbon nitride(GCN) Nanorod structure Polystyrene fibrous mat Photocatalytic fibers Oilfield-produced water(OPW)

Application of Geochemistry and VNIR Spectroscopy in Mapping Heavy Metal Pollution of Stream Sediments in the Takab Mining Area, NW of Iran

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Acta Geologica Sinica(English Edition) 2018年第6期92卷 2382-2394页

作者： parisa PIROOZFAR Samad ALIPOUR Soroush MODABBERI David COHEN Department of Geology Faculty of SciencesUrmia University School of Geology University of Tehran School of Biological Earth and Environmental SciencesNew South Wales University

This study considered the possibility of using visible and near infrared(VNIR) spectral absorption feature parameters(SAFPs) in predicting the concentration and mapping the distribution of heavy metals in sediments of the Takab area. In total, 60 sediment samples were collected along main streams draining from the mining districts and tailing sites, in order to measure the concentration of As, Co, V, Cu, Cr, Ni, Hg, Ti, Pb and Zn and the reflectance spectra(350–2500 nm). The quantitative relationship between SAFPs(Depth500 nm, R610/500 nm, R1344/778 nm, Area500 nm, Depth2200 nm, Area2200 nm, Asym2200 nm) and geochemical data were assessed using stepwise multiple linear regression(SMLR) and enter multiple linear regression(EMLR) methods. The results showed a strong negative correlation between Ni and Cr with Area2200 nm, a significant positive correlation between As and Asym2200 nm, Ni and Co with Depth2200 nm, as well as Co, V and total values with Depth500 nm. The EMLR method eventuated in a significant prediction result for Ni, Cr, Co and As concentrations based on spectral parameters, whereas the prediction for Zn, V and total value was relatively weak. The spatial distribution pattern of geochemical data showed that mining activities, along with the natural weathering of base metal occurrences and rock units, has caused high concentrations of heavy metals in sediments of the Sarough River tributaries.

关键词： heavy metals SAFPs VNIR spectroscopy multiple linear regression Takab Iran

Polyvinylpolypyrrolidonium tribromide as new and metal-free catalyst for the formylation and trimethylsilylation of hydroxyl group

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Chinese Chemical Letters 2011年第10期22卷 1207-1210页

作者： Arash Ghorbani-Choghamarani Hamid Goudarziafshar parisa Zamani Department of Chemistry Faculty of ScienceIlam UniversityP.O.Box 69315516 Ilam.Iran

Trimethylsilylation of alcohols was achieved using 1,1,1,3,3,3-hexamethyldisilazane（HMDS） as silylating agent,in the presence of polyvinylpolypyrrolidonium tribromide in acetonitrile at room *** a variety of alcohols were converted into alkyl formates by ethyl formate and a catalytic amount of polyvinylpolypyrrolidonium tribromide under solvent free conditions at room temperature.

关键词： Polyvinylpolypyrrolidone Polyvinylpolypyrrolidonium tribromide Formylation Silylation Ethyl format 1 1 1 3 3 3-Hexamethyl-disilazane(HMDS)

Electrocatalytic determination of L-cysteine using a modified carbon nanotube paste electrode:Application to the analysis of some real samples

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Chinese Chemical Letters 2012年第8期23卷 981-984页

作者： Malihe Ahmadipour Mohammad Ali Taher Hadi Beitollahi Rahman hosseinzadeh Department of Chemistry Shahid Bahonar University of KermanP.O.Box 76175-133KermanIran Young Researchers Society Shahid Bahonar University of KermanP.O.Box 76175-133KermanIran Environment Department Research Institute of Environmental SciencesInternational Center for ScienceHigh Technology&Environmental SciencesKermanIran Department of Organic Chemistry Faculty of ChemistryUniversity of MazandaranBabolsarIran

The electrooxidation of L-cysteine（L-Cys） was studied using a benzoylferrocene（BF） modified multi-wall carbon nanotube paste electrode（BFCNPE） using cyclic voltammetry（CV）,square wave voltammetry（SWV） and chronoamperometry（CHA）.Under optimum pH in CV the oxidation of L-Cys occurs at a potential about 215 mV less positive than that at the surface of unmodified carbon paste *** catalytic oxidation peak currents were dependent on the L-Cys concentration and a linear calibration curve was obtained in the range 0.7-350.0 mmol/L of L-Cys with SWV *** detection limit（3s） was determined as 0.1 mmol/*** method was also used for the determination of L-Cys in some real samples.

关键词： L-Cysteine Carbon paste electrode Carbon nanotubes Voltammetry

Enhancement of the transfection efficiency of DNA into Crocus sativus L. cells via PEI nanoparticles

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Journal of Integrative Agriculture 2018年第8期17卷 1768-1778页

作者： Behnam Firoozi Nasser Zare Omid Sofalian parisa Sheikhzade-Mosadegh Department of Agronomy and Plant Breeding Faculty of Agriculture and Natural Resources University of Mohaghegh Ardabili

Over the past decade, several natural and synthetic cationic polymers have been utilized for gene delivery into cells. Among them, polyethylenimine(PEI) was used for gene therapy successfully. The present study investigated the effect of PEI and ultrasound waves on ssD NA delivery into saffron cells. Gel retardation, dynamic light scattering(DLS) and scanning electron microscopy(SEM) assays were employed to determine the physicochemical properties of PEI/f-DNA polyplex(complex of PEI and fluorescently labeled DNA). Moreover, the cytotoxicity of PEI, PEI/f-DNA polyplex and ultrasound were investigated on saffron cells at different concentrations. The gel retardation results indicated that the formation and neutralization of the PEI/f-DNA polyplex were completed at N/P=5. The particle size distribution of the polyplexes was from 50 to 122 nm. The experimental results revealed that the cytotoxicity of the PEI/f-DNA polyplex was lower than that of PEI alone, hence the cells showed both dose-and exposure duration-dependent responses. Furthermore, the viability of saffron cells declined extremely after 5 and 10 min sonication but this reduction was not significant at 2 min exposure duration. The results also indicated that the combined utilization of ultrasound and PEI nanoparticles increased the transfection efficiency of saffron cells up to two times higher than those obtained by PEI or ultrasound separately.

关键词： PEI/f-DNA polyplex plant cell transfection saffron sonication

Sensitivity analysis of ground motion prediction equation using next generation attenuation dataset

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Geodesy and Geodynamics 2020年第1期11卷 40-45页

作者： Sina Sabermahani parisa Ashjanas Department of Earth Science Graduate University of Advanced TechnologyIran

Seismic hazard assessment is an important stage in earthquake *** the ground motion prediction equation(GMPE)has a key role in seismic hazard assessment,it is necessary to determine this equation as well as *** mutual seismic parameters,such as earthquake magnitude,distance,fault type,and site effect,are applied in *** ridge regression method is applied to find the relation between input seismic parameters and targets(PGA,PGV,PGD,SA(T=0.02 s),and SA(T=1 s)).Results of regression show that equations obtained in this study have a root mean square error(RMSE)of 90%.In the last part,GMPEs are inspected by sensitivity analysis through two methods:Sobol and Delta Moment-Independent *** results from the two methods were very similar to each other for each ***,the analysis shows that the most effective parameters in determining GMPEs are moment magnitude and shear wave velocity.

关键词： Ground motion prediction equation Ridge-regression Next generation attenuation Sobol Delta

Connectedness of cryptocurrency markets to crude oil and gold:an analysis of the effect of COVID-19 pandemic

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Financial Innovation 2024年第1期10卷 1382-1404页

作者： parisa Foroutan Salim Lahmiri Department of Supply Chain and Business Technology Management John Molson School of BusinessConcordia UniversityMontrealCanada

The notion that investors shift to gold during economic market crises remains unverified for many cryptocurrency *** paper investigates the connectedness between the 10 most traded cryptocurrencies and gold as well as crude oil markets pre-COVID-19 and during *** the application of various statistical techniques,including cointegration tests,vector autoregressive models,vector error correction models,autoregressive distributed lag models,and Granger causality analyses,we explore the relationship between these markets and assess the safe-haven properties of gold and crude oil for *** findings reveal that during the COVID-19 pandemic,gold is a strong safe-haven for Bitcoin,Litecoin,and Monero while demonstrating a weaker safe-haven potential for Bitcoin Cash,EOS,Chainlink,and *** contrast,gold only exhibits a strong safe-haven characteristic before the pandemic for Litecoin and ***,Brent crude oil emerges as a strong safe-haven for Bitcoin during COVID-19,while West Texas Intermediate and Brent crude oils demonstrate weaker safe-haven properties for Ether,Bitcoin Cash,EOS,and ***,the Granger causality analysis indicates that before the COVID-19 pandemic,the causal relationship predominantly flowed from gold and crude oil toward the cryptocurrency markets;however,during the COVID-19 period,the direction of causality shifted,with cryptocurrencies exerting influence on the gold and crude oil *** findings provide subtle implications for policymakers,hedge fund managers,and individual or institutional cryptocurrency *** results highlight the need to adapt risk exposure strategies during financial turmoil,such as the crisis precipitated by the COVID-19 pandemic.

关键词： Cryptocurrency market Connectedness Safe-haven Gold Crude oil Timeseries models COVID-19 pandemic