Adsorption of divalent lead ions from aqueous solution using low silica nano-zeolite X

Milad Rasouli,Mehdi Hafezi,Majid Rasouli,Nakisa Yaghobi 한국공업화학회 2012 Journal of Industrial and Engineering Chemistry Vol.18 No.6

The studies on adsorption of divalent lead from aqueous solution were conducted by varying various parameters such as contact time, pH, adsorbent dosage, concentration of adsorbate and temperature. The maximum adsorption efficiency was obtained in a contact time of 100 min, pH of 3.5–5, adsorbent dosage of 1.5 g/L, adsorbate concentration of 15 mg/L and temperature of 318 K. The adsorption kinetic of Pb2+onto low silica nano-zeolite X was discussed using different models and the pseudo-second order model provided the best correlation of the experimental data. Langmuir and Freundlich adsorption isotherms were employed in order to evaluate the optimum adsorption capacity of the adsorbent. Low silica nanozeolite X was found to be very effective and reached equilibrium in 100 min. The adsorption capacity of Pb2+ on low silica nano-zeolite X was found to be 909.09 mg/g in the optimum condition. The rate constant and thermodynamic parameters were calculated.

ON THE EXISTENCE OF POSITIVE SOLUTION FOR A CLASS OF NONLINEAR ELLIPTIC SYSTEM WITH MULTIPLE PARAMETERS AND SINGULAR WEIGHTS

Rasouli, S.H. Korean Mathematical Society 2012 대한수학회논문집 Vol.27 No.3

This study concerns the existence of positive solution for the following nonlinear system $$\{-div(|x|^{-ap}|{\nabla}u|^{p-2}{\nabla}u)=|x|^{-(a+1)p+c_1}({\alpha}_1f(v)+{\beta}_1h(u)),x{\in}{\Omega},\\-div(|x|^{-bq}|{\nabla}v|q^{-2}{\nabla}v)=|x|^{-(b+1)q+c_2}({\alpha}_2g(u)+{\beta}_2k(v)),x{\in}{\Omega},\\u=v=0,x{\in}{\partial}{\Omega}$$, where ${\Omega}$ is a bounded smooth domain of $\mathbb{R}^N$ with $0{\in}{\Omega}$, 1 < $p,q$ < N, $0{{\leq}}a<\frac{N-p}{p}$, $0{{\leq}}b<\frac{N-q}{q}$ and $c_1$, $c_2$, ${\alpha}_1$, ${\alpha}_2$, ${\beta}_1$, ${\beta}_2$ are positive parameters. Here $f,g,h,k$ : $[0,{\infty}){\rightarrow}[0,{\infty})$ are nondecresing continuous functions and $$\lim_{s{\rightarrow}{\infty}}\frac{f(Ag(s)^{\frac{1}{q-1}})}{s^{p-1}}=0$$ for every A > 0. We discuss the existence of positive solution when $f,g,h$ and $k$ satisfy certain additional conditions. We use the method of sub-super solutions to establish our results.

Does mudcake change the results of modeling gamma-gamma well-logging?

Rasouli Fatemeh S. 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.9

Among the different techniques available, nuclear methods, including gamma-gamma logging tools, are of special importance. Though the real environment which surrounds the drilled borehole is a complex fractured medium which the fluid can flow through the porosities, simulation studies generally use the traditional model of a homogeneous mixture of formation and the liquid. Considering a previously published study, which shows that modeling of fluid flow in fractured reservoirs and simulating the formation as an inhomogeneous fractured medium leads to different results compared with those of homogeneous mixture, here we study the effect of the presence of drilling fluid (mudcake) on the response of the detectors in both the models. To study this effect, a typical gamma-gamma logging tool was modeled by using the MCNPX Monte Carlo code. The results show that the responses of the detectors in the mixture model in the presence of various thicknesses of mudcake are sensitive to the density of the formation material. However, this effect is not notable in the inhomogeneous fractured medium. These results emphasize the importance of the model employed for simulation of the medium in gamma-gamma well-logging.

A comparison study between the realistic random modeling and simplified porous medium for gamma-gamma well-logging

Rasouli Fatemeh S. 한국원자력학회 2024 Nuclear Engineering and Technology Vol.56 No.5

The accurate determination of formation density and the physical properties of rocks is the most critical logging tasks which can be obtained using gamma-ray transport and detection tools. Though the simulation works published so far have considerably improved the knowledge of the parameters that govern the responses of the detectors in these tools, recent studies have found considerable differences between the results of using a conventional model of a homogeneous mixture of formation and fluid and an inhomogeneous fractured medium. It has increased concerns about the importance of the complexity of the model used for the medium in simulation works. In the present study, we have suggested two various models for the flow of the fluid in porous media and fractured rock to be used for logging purposes. For a typical gamma-gamma logging tool containing a137Cs source and two NaI detectors, simulated by using the MCNPX code, a simplified porous (SP) model in which the formation is filled with elongated rectangular cubes loaded with either mineral material or oil was investigated. In this model, the oil directly reaches the top of the medium and the connection between the pores is not guaranteed. In the other model, the medium is a large 3-D matrix of 1 cm3 randomly filled cubes. The designed algorithm to fill the matrix sites is so that this realistic random (RR) model provides the continuum growth of oil flow in various disordered directions and, therefore, fulfills the concerns about modeling the rock textures consist of extremely complex pore structures. For an arbitrary set of oil concentrations and various formation materials, the response of the detectors in the logging tool has been considered as a criterion to assess the effect of modeling for the distribution of pores in the formation on simulation studies. The results show that defining a RR model for describing heterogeneities of a porous medium does not effectively improve the prediction of the responses of logging tools. Taking into account the computational cost of the particle transport in the complex geometries in the Monte Carlo method, the SP model can be satisfactory for gamma-gamma logging purposes.

Cooperative Subcarrier Allocation and Power Allocation in the Downlink of an Amplify-and-Forward OFDM Relaying System

Rasouli, H.,Kong, H. Y.,Anpalagan, A. Springer-Verlag 2014 WIRELESS PERSONAL COMMUNICATIONS Vol.79 No.3

Preparation of anticorrosive cobalt-doped ZnO nano pigments by a combustion method; A comparison study between microwave irradiation and a conventional heating source

Sousan Rasouli 한양대학교 세라믹연구소 2011 Journal of Ceramic Processing Research Vol.12 No.6

In the present study, cobalt-doped ZnO nano pigments were synthesized by a solution gel combustion method using glycine fuel. A chamber furnace and microwave irradiation were used as heating sources. Products were characterized by X-ray diffraction, scanning-transmission electron microscopy and diffuse reflectance. The anticorrosive properties of the pigments obtained were investigated by electrochemical impedance spectroscopy. The results have shown that using glycine as the fuel pure ZnO phase was obtained directly by the two heating sources. Electron microscopy demonstrated quasi-spherical particles with a crystallite size of 49 nm for furnace-assisted and rod-like particles of 63 nm for the microwave-assisted procedure were obtained. The corrosion performance of the coating in 3% w/V NaCl solution was evaluated by electrochemical impedance spectroscopy (EIS) and polarization measurements. According to the measurements of EIS and electrochemical polarization,the coatings with a furnace-assisted pigment showed a higher corrosion resistance.

The effect of fuel-to-oxidizer ratio on the structure and photo-catalytic activity of TiO2 nanosheets prepared by a microwave-assisted combustion method

Sousan Rasouli,Fatemeh Oshani,Seyed Masoud Hashemi 한양대학교 세라믹연구소 2012 Journal of Ceramic Processing Research Vol.13 No.2

TiO2 nanosheets were synthesized by a combustion method using a metal nitrate solution combustion and urea fuel. Microwave irradiation was used as the heating source. X-ray diffraction, scanning and transmission electron microscopy as well as specific surface area analysis and Fourier transform infrared spectroscopy were performed to characterize the samples obtained. X-ray diffraction patterns revealed that the ratio of rutile/anatase phases varied from 25/75 to 69/31 as the fuel-tooxidizer (i.e. urea/titanyl nitrate) ratio changed from lean to rich. The crystallite size of the as-synthesized samples calculated by the Scherrer formula was 6.5-63 nm. From scanning and transmission microscopy images flaky particles with loose packed agglomerates in the form of nanosheets were detected. Due to the smaller crystallite size and higher content of the anatase phase, the fuel lean sample seemed to be a better candidate for photo-catalytic functions. TiO2 nanosheets were synthesized by a combustion method using a metal nitrate solution combustion and urea fuel. Microwave irradiation was used as the heating source. X-ray diffraction, scanning and transmission electron microscopy as well as specific surface area analysis and Fourier transform infrared spectroscopy were performed to characterize the samples obtained. X-ray diffraction patterns revealed that the ratio of rutile/anatase phases varied from 25/75 to 69/31 as the fuel-tooxidizer (i.e. urea/titanyl nitrate) ratio changed from lean to rich. The crystallite size of the as-synthesized samples calculated by the Scherrer formula was 6.5-63 nm. From scanning and transmission microscopy images flaky particles with loose packed agglomerates in the form of nanosheets were detected. Due to the smaller crystallite size and higher content of the anatase phase, the fuel lean sample seemed to be a better candidate for photo-catalytic functions.

Gender Based Violence among Afghan Communities in the UK

Zahra RASOULI 이화여자대학교 아시아여성학센터 2016 이화여자대학교 아시아여성학센터 학술대회자료집 Vol.2016 No.1

Power and Control is at the heart of Gender Based Violence (GBV) and closely related to women empowerment. Patriarchal system and lack of education and awareness are some of the main causes of Afghan women in the UK to suffer from Gender Based Violence. While to a fair extend help is provided for the victims of GBV in the UK, Often Afghan women fail to seek help. Partly this could be summarized to lack of knowledge of the functioning system. However, most importantly the victims of GBV are imprisoned by the strong transnational patriarchal and cultural dominance of their home country’s norms and traditions.

Anaerobic co-digestion of sewage sludge and Cladophora green algae: Investigation of synergistic effects and Optimization of substrate composition ratio

Majid Rasouli,Mahdi Dini,Behnam Ataeiyan 대한환경공학회 2023 Environmental Engineering Research Vol.28 No.5

Activity-based models of travel demand: promises, progress and prospects

Soora Rasouli,Harry Timmermans 서울시립대학교 도시과학연구원 2014 도시과학국제저널 Vol.18 No.1

Because two decades have almost passed since the introduction of activity-based modelsof travel demand, this seems the right time to evaluate progress made in the developmentand application of these models. This invited paper seeks to discuss the initial promisesof activity-based models as an alternative to four-step and tour-based models, summarizeprogress made and identify still unsolved issues that require further research.