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Treatment of fir wood with chitosan and polyethylene glycol

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Journal of Forestry Research 2016年第4期27卷 959-966页

作者： zahra Nowrouzi Behbood Mohebby Habibollah Younesi Tarbiat Modares University Noor Iran

Chitosan is a natural biopolymer, derived from chitin, which is used for wood modification. Polyethylene glycol（PEG） was reacted with wood to provide possible fixation of the chitosan to wood. Wood blocks were treated with chitosan and PEG, as well as pre-treatment with the PEG at different temperatures and further reaction with the chitosan. The samples were soaked in water to study leaching of the chemicals, water absorption, swelling, as well as anti-swelling efficiency. Any prior reaction of the wood with PEG provided better reaction to the *** was increased after the treatment of the wood with PEG. Swelling was reduced in the PEG-treated wood blocks as well as the pre-treated samples. Chitosan was not able to protect wood against water penetration： the treated samples showed more water absorption and ***, pre-treatment of the samples decreased swelling in the wood, and the density was not noticeably affected by the treatments. Heating during the treatment caused more reduction in swelling for PEG–chitosan treated samples.

关键词： chitosan swelling glycol polyethylene chemicals leaching dried prior chitin fixation

Effects of Silver Nanoparticles on the Activities of Soil Enzymes Involved in Carbon and Nutrient Cycling

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Pedosphere 2018年第2期28卷 209-214页

作者： Frieda EIVAZI zahra AFRASIABI Elizabeth JOSE Department of Agriculture and Environmental Sciences Lincoln University Department of Environmental Studies Soka University Department of Physiology and Cell Biology The Ohio State University

Soils are continuously exposed to large amounts of engineered nanoparticles, especially silver nanoparticles (AgNPs), which can affect the activity, stability, and specificity of microbial enzymes. Therefore, the measurement of specific enzyme activity can be used to identify major changes in soil environments. Accordingly, the aim of the present study was to investigate the effects of AgNPs on soil enzymes that play critical roles in mineralizing carbon and nutrients in soil. Soil samples (silt loam and sandy loam) were collected from the surface layer (0–15 cm) of a field at the George Washington Carver Farm, Lincoln University of Missouri, USA. The soils were then treated with AgNP solutions at 0, 1 600, or 3 200 μg Ag kg^(-1) dry soil, using either 10- or 50-nm AgNPs and a randomized complete block design, with three replicates per treatment. The AgNP-treated soil samples were homogenized and incubated for one month, and soil acid phosphatase, β-glucosaminidase, β-glucosidase, and arylsulfatase activities were measured after one hour, one week, and one month of incubation. The activities of all four enzymes were reduced by AgNP treatment after one hour and one ***, AgNP size had no effect. After one month of incubation, the AgNP treatments had mixed effects, which suggests that soil enzymes are only affected on a short-term basis. Further studies are required to determine the mechanisms by which AgNPs reduce soil enzyme activity.

关键词： engineered nanoparticles nanotechnology nanoparticle concentration nanoparticle size soil environment

Effect of Essential Oil of Zhumeria majdae on Morphine Tolerance and Dependence in Mice

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Chinese Journal of Integrative Medicine 2020年第9期26卷 683-687页

作者： zahra Ehtemami Hamed Shafaroodi Jinous Asgarpanah Department of Pharmacognosy Faculty of Pharmacy and Pharmaceutical SciencesTehran Medical SciencesIslamic Azad UniversityTehranIran Department of Pharmacology School of MedicineTehran University of Medical SciencesTehranIran

Objective:To evaluate the effects of Zhumeria majdae essential oil(ZMEO)on morphine dependence and tolerance in ***:ZMEO(10,20,and 40 mg/kg)and clonidine(0.1 mg/kg)as the positive control were injected intraperitoneally(i.p.).The effect of ZMEO and clonidine on the dependence were evaluated by counting the number of jumps induced by naloxone(5 mg/kg)while the tolerance was evaluated by the tail-flick ***:ZMEO at the dose of 10 mg/kg during the development period led to a significant inhibition of morphine tolerance(P<0.01),while it led to reduced morphine dependence with the doses of 20 and 40 mg/*** at two dose levels of 20 and 40 mg/kg indicated significant antinociceptive activity(P<0.01),and significantly reduced the withdrawal signs(number of jumps)of mice(P<0.01).Conclusions:ZMEO had significant effects on morphine tolerance and *** linalool rich essential oil of Zmajdae plays a major role in the reduction of tolerance and dependence induced by morphine.

关键词： Zhumeria majdae morphine dependence tolerance

Spatial downscaling of climate variables using three statistical methods in Central Iran

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Journal of Mountain Science 2018年第3期15卷 606-617页

作者： zahra JABERALANSAR Mostafa TARKESH Mehdi BASSIRI Department of Natural Resources Isfahan University of Technology Research Division of Natural Resources Isfahan Agricultural and Natural Resources Research and Education CenterAREEO

Spatial downscaling methods are widely used for the production of bioclimatic variables(e.g. temperature and precipitation) in studies related to species ecological niche and drainage basin management and planning. This study applied three different statistical methods, i.e. the moving window regression(MWR), nonparametric multiplicative regression(NPMR), and generalized linear model(GLM), to downscale the annual mean temperature(Bio1) and annual precipitation(Bio12) in central Iran from coarse scale(1 km × 1 km) to fine scale(250 m ×250 m). Elevation, aspect, distance from sea and normalized difference vegetation index(NDVI) were used as covariates to create downscaled bioclimatic variables. Model assessment was performed by comparing model outcomes with observational data from weather stations. Coefficients of determination(R2), bias, and root-mean-square error(RMSE) were used to evaluate models and covariates. The elevation could effectively justify the changes in bioclimatic factors related to temperature and precipitation. Allthree models could downscale the mean annual temperature data with similar R2, RMSE, and bias values. The MWR had the best performance and highest accuracy in downscaling annual precipitation(R2=0.70; RMSE=123.44). In general, the two nonparametric models, i.e. MWR and NPMR, can be reliably used for the downscaling of bioclimatic variables which have wide applications in species distribution modeling.

关键词： Statistical models Climatic data Elevation Spatial resolution Temperature Precipitation

A New Logarithmic Family of Distributions: Properties and Applications

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Computers, Materials & Continua 2021年第1期66卷 919-929页

作者： Yanping Wang Zhengqiang Feng Almaspoor zahra Central South University Business School ChangshaChina Hunan International Business Vocational College ChangshaChina Department of Statistics Yazd UniversityYazdIran

In recent years,there has been an increased interest among the researchers to propose new families of distributions to provide the best fit to lifetime data with monotonic(increasing,decreasing,constant)and non-monotonic(unimodal,modified unimodal,bathtub)hazard *** further carry this area of research and propose a new family of lifetime distributions called a new logarithmic family via the T-X family *** the proposed family,explicit expressions for some mathematical properties along with the estimation of parameters through Maximum likelihood method are discussed.A sub-model,called a new logarithmic Weibull distribution is taken *** proposed model is very flexible and can be used to model data with increasing,decreasing,modified unimodal or bathtub shaped hazard *** maximum likelihood estimators of the model parameters are *** assess the behavior of the maximum likelihood estimators,a comprehensive Monte Carlo simulation study has been carried ***,the potentiality of the new model is shown via analyzing two real data sets taken from reliability engineering and biomedical *** comparison of the proposed model is made with the other well-known competitors such as(i)the three parameters exponentiated Weibull and Marshall–Olkin Weibull distributions and(ii)a four-parameter beta Weibull *** practical applications show that the proposed model performs much better than the competitive models and can be used as a good candidate model to analyze data in engineering,medical sciences and other related fields.

关键词： Weibull distribution moments order statistic residual life function maximum likelihood estimation

Large Signal Circuit Model of Two-Section Gain Lever Quantum Dot Laser

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Chinese Physics Letters 2012年第11期29卷 85-87页

作者： Ashkan Horri Seyedeh zahra Mirmoeini Rahim Faez Young Researchers Club Arak BranchIslamic Azad UniversityArakIran Department of Electrical Engineering Arak BranchIslamic Azad UniversityArakIran Department of Electrical Engineering Sharif University of TechnologyTehranIran

An equivalent circuit model for the design and analysis of two-section gain lever quantum dot(QD)laser is *** model is based on the three level rate equations with two independent carrier populations and a single longitudinal optical *** using the presented model,the effect of gain lever on QD laser performances is *** results of simulation show that the main characteristics of laser such as threshold current,transient response,output power and modulation response are affected by differential gain ratios between the two-sections.

关键词： laser Signal Quantum

Selective separation of gallium from aluminum in SDS–Ga–Al and SDS–Ga–Al–fluoride systems by ion flotation

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Journal of Central South University 2017年第4期24卷 789-795页

作者： Bahri zahra Rezai Bahram1 Kowsari Elaheh Department of Mining and Metallurgical Engineering Amirkabir University of TechnologyTehran 158754413Iran Department of Chemistry Amirkabir University of TechnologyTehran 15916-34311Iran

Selective separation of gallium from aluminum by ion flotation using sodium dodecyl sulfate(SDS) as an anionic surfactant and fluoride as an inorganic ligand was investigated. The experimental results were analyzed using the stability constants and speciation diagrams of fluoride metal complexes. The presence of fluoride in the solution has a positive influence upon the separation of gallium from aluminum. The results show that increasing the fluoride concentration makes a more effective separation of gallium from aluminum because of a simultaneous increase in the complexion of aluminum with fluoride and a change in the electrical charge of the aluminum(ALF_4^-). The dehydration model of LIU and DOYLE was also applied to compare the ion flotation and the selectivity coefficients of gallium over aluminum with experimental results.

关键词： ion flotation gallium(Ⅲ) selective separation inorganic ligand

Modeling the COVID-19 Pandemic Dynamics in Iran and China

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Computers, Materials & Continua 2021年第5期67卷 2111-2122页

作者： Jin Zhao Zubair Ahmad zahra Almaspoor School of Finance Shanghai Lixin University of Accounting and FinanceShanghaiChina Department of Statistics Yazd UniversityYazdIran

The epidemic outbreak COVID-19 was rst detected in the Wuhan city of China and then spread *** is of great interest to the researchers for its high rate of infection spread and its signicant number of fatalities.A detailed scientic analysis of this phenomenon is yet to ***,it is of interest of governments and other responsible institutions to have the right facts and gures to take every possible necessary action such as an arrangement of the appropriate quarantine activities,estimation of the required number of places in hospitals,assessment of the level of personal protection,and calculating the rate of isolation of infected persons,among *** this article,we compare the COVID-19 pandemic dynamics between the two most affected Asian countries Iran and China's *** provide a convenient method of data comparison that can be helpful for both governmental and private organizations to arrange the appropriate quarantine ***,a statistical model is suggested to provide the best characterization of the COVID-19 daily deaths data of Iran and *** analyzing daily death events,we observed that the proposed model provides a better description of the COVID-19 events,and therefore,can be used as a good candidate model for predicting them.

关键词： Coronavirus COVID-19 pandemic China Iran mathematical modeling statistical met

Canopy cover or remotely sensed vegetation index,explanatory variables of above-ground biomass in an arid rangeland,Iran

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Journal of Arid Land 2018年第5期10卷 767-780页

作者： Fatemeh PORDEL Ataollah EBRAHIMI zahra AZIZI Department of Range and Watershed Management Shahrekord University Department of RS-GIS Science and Research Branch Islamic Azad University

Estimation of above-ground biomass is vital for understanding ecological processes. Since direct measurement of above-ground biomass is destructive, time consuming and labor intensive, canopy cover can be considered as a predictor if a significant correlation between the two variables exists. In this study, relationship between canopy cover and above-ground biomass was investigated by a general linear regression model. To do so, canopy cover and above-ground biomass were measured at 5 sub-life forms（defined as life forms grouped in the same height classes） using 380 quadrats, which is systematic-randomly laid out along a 10-km transect, during four sampling periods（May, June, August, and September） in an arid rangeland of Marjan, Iran. To reveal whether obtained canopy cover and above-ground biomass of different sampling periods can be lumped together or not, we applied a general linear model（GLM）. In this model, above-ground biomass was considered as a dependent or response variable, canopy cover as an independent covariate or predictor factor and sub-life forms as well as sampling periods as fixed factors. Moreover, we compared the estimated above-ground biomass derived from remotely sensed images of Landsat-8 using NDVI（normalized difference vegetation index）, after finding the best regression line between predictor（measured canopy cover in the field） and response variable（above-ground biomass） to test the robustness of the induced model. Results show that above-ground biomass（response variable） of all vegetative forms and periods can be accurately predicted by canopy cover（predictor）, although sub-life forms and sampling periods significantly affect the results. The best regression fit was found for short forbs in September and shrubs in May, June and August with R^2 values of 0.96, 0.93 and 0.91, respectively, whilst the least significant was found for short grasses in June, tall grasses in August and tall forbs in June with R^2 values of 0.71, 0.73 and 0.75, r

关键词： rangeland biomass non-destructive method arid ecosystems NDVI