نتایج جستجو برای: kinetics activation energy characterization operational conditions pseudo second order

تعداد نتایج: 3462436  

this thesis attempts to investigate the effects of prelistening activities on enhancing iranian efl learners` listening comprehension. the present study investigated ways in which learners` background knowledge could be activated in order to enhance their l2 listening comprehension by limiting the number of possible text interpretations prior to listening. the experiments conducted in this study examined the effect of prior knowledge and vocabulary teaching on iranian efl learners listening comprehension. the current study has two purposes: one is to investigate the effect of background knowledge on the second language listening comprehension of iranian intermediates and the other is to determine whether second language is facilitated by the introduction of unknown vocabularies in the form of prelistening activities. to conduct the study different instruments such as listening proficiency test and four listening tests such as pre and posttests were used and various statistical processes and techniques including paired-sample t-test, and analysis of variance (anova) were used. the findings of this study supported all three hypotheses tested. differences were found between the means of preteaching vocabulary variable, the background knowledge activation variable, and mean difference between these two strategies variable. subjects scored higher when the unknown words were taught in advance. likewise, subjects scored higher when they were asked some relevant questions about the topic than on those without them. there was, in addition, a significant difference between the means of preteaching vocabulary strategy and background knowledge activation strategy. in fact, preteaching vocabulary had a better effect in enhancing the students’ listening comprehension, in comparison to background knowledge activation strategy.

پایان نامه :دانشگاه آزاد اسلامی - دانشگاه آزاد اسلامی واحد تهران مرکزی - دانشکده زبانهای خارجی 1390

this thesis attempts to investigate the effects of prelistening activities on enhancing iranian efl learners` listening comprehension. the present study investigated ways in which learners` background knowledge could be activated in order to enhance their l2 listening comprehension by limiting the number of possible text interpretations prior to listening. the experiments conducted in this stud...

Dimerization process is essential for producing copolymers. The features of dimerization process like thermal-oxidative degradation should be well known to reach maximum efficiency and a superior reactor design. Also, the degradation mechanism of biodegradable polymers is important during sterilization processes. Thermal-oxidative degradation of PGA, PLLA, and their binary copolymers was invest...

Journal: :international journal of environmental research 2015
f. sharifipour s. hojati a. landi a. faz cano

a good understanding of adsorption equilibrium and thermodynamics is required to design and operate an adsorption process. this study was conducted to assess the adsorption percentage of pb2+ ions as a function of contact time, solution ph and temperatures, and adsorbent dosage through a series of batch experiments. the methods including zeta potentials, specific surface area measurements and t...

2014

This paper presents the feasibility of removal of MB dye from aqueous solution using activated carbon prepared from Usoro fiber (Adenia lobata). FTIR analysis revealed that many functional groups were present on the surface of the adsorbent. The adsorption Kinetics was analyzed by pseudo first order, pseudo second order and intra particle diffusion kinetics models. Results showed that MB adsorp...

Mohsen Hosseinzadeh Seyed Morteza Masoudpanah Seyyed Ali Seyyed Ebrahimi, Shahram Raygan,

In this study, the removal of cadmium and lead ions from aqueous solution by nanocrystalline magnetite was investigated. The nanocrystalline magnetite was synthesized by mechanochemical activation of hematite in a high energy planetary mill in argon atmosphere for 45 hours. The ability of the synthesized nanocrystalline magnetite for removal of Cd(II) and Pb(II) from aqueous solutions was studi...

ژورنال: طلوع بهداشت یزد 2021

Introduction: Dyes are materials with a complex structure that enter the environment from textile processes such as dyeing and washing. The aim of this study was to investigate the efficiency of the absorption process using Zeolite @ ZnO in removing methylene blue dye from textile wastewater. Methods: The structure and morphology of nanoparticles were examined using XRF, FTIR and FESEM techniq...

In this work, orange (Citrus sinensis) peels biochar (OPBC) were prepared by one-step H2SO4 activation for Methylene Blue (MB) adsorption from aqueous solution. The physicochemical properties of OPBC were characterized using instrumental analyses such as CHNS-O analyzer, Fourier Transform InfraRed (FT-IR) spectroscopy, Scanning Electron Microscopy (SEM), X-Ray Diffract...

A. Fakhri A. R. Zekri K. Zare O. Moradi

The removal of Cd2+ and Pb2+ ions from wastewater using p-tert-butyl-calix[4] arene was investigated in terms of initial pH, initial concentration, adsorbent dosage, contact time and temperature. The maximum adsorption occurred at the pH value of 6. The adsorbent studied exhibits high efficiency for Cd (II)and Pb (II) adsorption and the equilibrium states could be achieved in 10 min. Adsorption...

Journal: :Green Energy & Environment 2021

Abstract In this work, characterization and kinetics of CO2 absorption in potassium carbonate (K2CO3) solution promoted by diethylenetriamine (DETA) were investigated. Kinetics measurements performed using a stirred cell reactor the temperature range 303.15–323.15 K total concentration up to 2.5 kmol m?3. The density, viscosity, physical solubility, diffusivity rate determined. reaction between...

In this work, adsorption kinetics were investigated in order to remove the acid blue 62 off the aqueous solutions using mesoporous silicate SBA-15 loaded with tannic acid (tannin-SBA-15). Nitrogen adsorption and desorption test (BET), X-ray diffraction (XRD) and Fourier transform infra-red spectroscopy (FT-IR) analysis characterize synthesized composite. The impacts of some parameters such as P...

نمودار تعداد نتایج جستجو در هر سال

با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید