Zn (II) removal by amino-functionalized magnetic nanoparticles: Kinetics, isotherm, and thermodynamic aspects of adsorption

Nahid Ghasemi,Maryam Ghasemi,Saleh Moazeni,Parisa Ghasemi,Njud S. Alharbi,Vinod Kumar Gupta,Shilpi Agarwal,Irina V. Burakova,Alexey G. Tkachev 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.62 No.-

In this study, a novel adsorbent, dioctylphetalate triethylenetetraamine magnetic nanoparticles (DOP-TETA-MNP) via a solvent-free procedure were synthesized for the removal of Zn (II) ions from aqueous solution. The morphological and anatomical characterization was investigated by various analytical techniques such as FTIR and SEM. Experimental data from evaluation of various influential parameters such as initial pH (2–7), initial ion concentration (5–20 mg/L), adsorbent dose (0.005–0.040 g), contact time (5–120 min) and temperature (308–333 K) of the solution were carried out using a batch adsorption method. DOP-TETA-MNP can be simply separated from aqueous solution with magnetic separations at low magnetic field. The kinetic data of Zn (II) ions were found to follow the pseudo-second-order kinetic model and the equilibrium data of ions sorption were well described by Langmuir isotherm model. The maximum monolayer sorption capacity of Zn (II) was estimated to be 24.21 mg/g at temperature of 333 K. Thermodynamic analyses show that the adsorption process is exothermic and spontaneous.

Chromium(III) Complex Obtained from Dipicolinic Acid: Synthesis, Characterization, X-Ray Crystal Structure and Electrochemical Studies

Ghasemi, Khaled,Rezvani, Ali Reza,Razak, Ibrahim Abdul,Moghimi, Abolghasem,Ghasemi, Fatemeh,Rosli, Mohd Mustaqim Korean Chemical Society 2013 Bulletin of the Korean Chemical Society Vol.34 No.10

The synthesis, X-ray crystallography, spectroscopic (IR, UV-vis), and electrochemical properties of the title compound, $[H_3O][Cr(dipic)_2][H_3O^+.Cl^-]$ (1), ($H_2dipic$ = 2,6-pyridinedicarboxylic acid), are reported. This complex crystallizes in the monoclinic space group Cc with a = 14.9006(10) ${\AA}$, b = 12.2114(8) ${\AA}$, c = 8.6337(6) ${\AA}$, ${\alpha}=90.00^{\circ}$, ${\beta}=92.7460(10)^{\circ}$, ${\gamma}=90.00^{\circ}$, and V = 1569.16(18) ${\AA}^3$ with Z = 4. The hydrogen bonding and noncovalent interactions play roles in the stabilization of the structure. In order to gain a better understanding of the most important geometrical parameters in the structure of the complex, atoms in molecules (AIM) method at B3LYP/6-31G level of theory has been employed.

A novel agricultural waste based adsorbent for the removal of Pb(II) from aqueous solution: Kinetics, equilibrium and thermodynamic studies

M. Ghasemi,Mu. Naushad,N. Ghasemi,Y. Khosravi-fard 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.2

Fig sawdust was used as a precursor for the production of activated carbon by chemical activation withH3PO4. The developed Fig sawdust activated carbon (FSAC) was used as a biosorbent for the removal ofPb(II) from aqueous solution. Highest adsorption of Pb(II) (95.8%) was found at pH 4. Equilibrium datafitted very well with the Langmuir isotherm model. Maximum adsorption capacity was determined80.645 mg g1 at pH 4. Kinetic studies demonstrated that the adsorption followed a pseudo second orderkinetics model. The negative value of DG8 confirmed the feasibility and spontaneity of FSAC for Pb(II)adsorption.

Adsorption of Pb(II) from aqueous solution using new adsorbents prepared from agricultural waste: Adsorption isotherm and kinetic studies

M. Ghasemi,M. Naushad,N. Ghasemi,Y. Khosravi-fard 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.4

The main goal of this study was to evaluate the performance of two new adsorbents, ash and Fe nanoparticles loaded ash (nFe-A) for the removal of Pb(II) from aqueous solution. Batch experiments were performed as a function of various experimental parameters. The adsorption studies included both equilibrium adsorption isotherms and kinetics. Equilibrium data fitted very well with the Langmuir isotherm model. Kinetics studies showed better applicability for pseudo-second-order model for both adsorbents. The regeneration studies showed promising regeneration potential of these adsorbents. The breakthrough capacities of ash and nFe-A for Pb(II) removal was found 25 and 30 mg g 1, respectively.

Chromium(III) Complex Obtained from Dipicolinic Acid: Synthesis, Characterization, X-Ray Crystal Structure and Electrochemical Studies

Khaled Ghasemi,Ali Reza Rezvani,Ibrahim Abdul Razak,Abolghasem Moghimi,Fatemeh Ghasemi,Mohd Mustaqim Rosli 대한화학회 2013 Bulletin of the Korean Chemical Society Vol.34 No.10

The synthesis, X-ray crystallography, spectroscopic (IR, UV-vis), and electrochemical properties of the title compound, [H3O][Cr(dipic)2] [H3O+.Cl−] (1), (H2dipic = 2,6-pyridinedicarboxylic acid), are reported. This complex crystallizes in the monoclinic space group Cc with a = 14.9006(10) Å, b = 12.2114(8) Å, c = 8.6337(6) Å, α = 90.00°, β = 92.7460(10)°, γ = 90.00°, and V = 1569.16(18) Å3 with Z = 4. The hydrogen bonding and noncovalent interactions play roles in the stabilization of the structure. In order to gain a better understanding of the most important geometrical parameters in the structure of the complex, atoms in molecules (AIM) method at B3LYP/6-31G level of theory has been employed.

Investigation of Microstructure and Wear Properties of Plasma Nitrided Astaloy Mo

Mahsa Haji Ghasemi,Behrooz Ghasemi,Hamid Reza Mohamadian Semnani 대한금속·재료학회 2019 METALS AND MATERIALS International Vol.25 No.4

In this research, plasma nitridation is carried out on the as-sintered and hardened Astaloy Mo in order to improve the wearbehavior of PM parts. The starting materials including pre-alloyed powders with 0.8% graphite were pressed at diff erentpressures. Next, the specimens were sintered at 1120 °C for 30 min, in the N 2 /H 2 atmosphere. The eff ects of density and coolingrate were studied on the microhardness, microstructure, and wear performance of as-sintered and hardened specimens. X-ray technique, scanning electron microscopy, and energy dispersive spectroscopy were used for phase transformation,morphology characterization, and elemental analysis, respectively. The results showed that plasma nitridation and an increasein cooling rate and density up to 6.8 g/cm 3 resulted in a change in wear resistance. Moreover, the wear performance of densesamples was decreased due to the enhanced three-body abrasive mechanism.

Sulfur-Emission-Free Process of Molybdenum Carbide Synthesis by Lime-Enhanced Molybdenum Disulfide Reduction with Methane

Ghasemi, Samad,Abbasi, Mohammad Hasan,Saidi, Ali,Kim, Jae Yul,Lee, Jae Sung American Chemical Society 2011 INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH - Vol.50 No.23

<P>To investigate a sulfur-emission-free process of molybdenum carbide synthesis from molybdenite, the reaction pathways of MoS<SUB>2</SUB> reduction with methane in the presence of lime (CaO) have been studied. A mixture of MoS<SUB>2</SUB> + 2CaO was reduced isothermally with CH<SUB>4</SUB> in a microreactor, and the composition of effluent gases and the reduced fraction were determined as a function of reaction time. Analysis of the solid phase at different reaction times at 800 °C showed the formation of CaMoO<SUB>4</SUB> as an intermediate phase. Hence, the reaction pathways proposed for reduction of MoS<SUB>2</SUB> + CaO with CH<SUB>4</SUB> involves the direct reduction of MoS<SUB>2</SUB> with CH<SUB>4</SUB> to form Mo<SUB>2</SUB>C and sulfur-containing gases. The sulfur-containing gases are captured by CaO to form CaS, CO(g), CO<SUB>2</SUB>(g), and H<SUB>2</SUB>O(g). The unreacted MoS<SUB>2</SUB> is oxidized by CO<SUB>2</SUB>(g) and H<SUB>2</SUB>O(g) to form MoO<SUB>3</SUB>(g), which reacted with CaO to form CaMoO<SUB>4</SUB> on CaO particles. Finally, CaMoO<SUB>4</SUB> and remaining MoS<SUB>2</SUB> are further reduced with CH<SUB>4</SUB>. Characterization of solid samples was carried out by XRD, CHN, and FE-SEM equipped with EDS, providing results consistent with the proposed reaction pathways. Carbon content of solid sample increased with reduction time, and in fully reduced sample at 800 °C it was well above the stoichiometric amount indicating considerable excess carbon deposition due to CH<SUB>4</SUB> cracking.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/iecred/2011/iecred.2011.50.issue-23/ie201860h/production/images/medium/ie-2011-01860h_0010.gif'></P>

Hair Follicle as a Source of Pigment-Producing Cells for Treatment of Vitiligo: An Alternative to Epidermis?

Ghasemi Mahshid,Bajouri Amir,Shafiiyan Saeed,Aghdami Nasser 한국조직공학과 재생의학회 2020 조직공학과 재생의학 Vol.17 No.6

To discuss the advantages and limitations of hair follicle-derived cell transplantation (FCT) in vitiligo, compared to the epidermal cell transplantation (ECT), and the knowledge gap which is required to be bridged. The papers relevant to the purpose was reviewed. Surgical approaches for treating vitiligo are based on the idea of replenishing lost melanocytes. Skin and hair follicles as the main sources of melanocytes have been applied for this purpose transferring the whole tissue or tissue-derived cell suspension to the vitiligo lesions. Considering the differences between hair follicle and epidermis in terms of the constituting cell populations, phenotype and function of melanocytes, and micro-environmental factors, different response of vitiligo patients to treatment with FCT or ECT would be expected theoretically. However, there is currently a lack of evidence on such a difference. However, ECT appears to be a more feasible, less time-consuming, and more comfortable treatment for both physicians and patients. Although the current evidence has not shown a significant difference between ECT and FCT in terms of efficacy, ECT appears to be more feasible specifically in the treatment of large lesions. However, further randomized controlled clinical trials with larger sample sizes and longer follow-up durations are required to be conducted to draw a definite conclusion on comparing FCT with ECT in terms of the safety, efficacy, durability of the therapeutic effects, and indications in vitiligo patients.

Flexural strengthening of continuous unbonded post-tensioned concrete beams with end-anchored CFRP laminates

Ghasemi, Saeed,Maghsoudi, Ali A.,Bengar, Habib A.,Ronagh, Hamid R. Techno-Press 2015 Structural Engineering and Mechanics, An Int'l Jou Vol.53 No.6

This paper provides the results of an experimental investigation into the flexural behavior of continuous two-span unbonded post-tensioned high strength concrete (HSC) beams, strengthened by end-anchored CFRP laminates of different configurations in the hogging region. Implementing two different configurations of end-anchorage systems consisting of steel plates and bolts and carefully monitoring the development of strains throughout the load history using sufficiently large number of strain gauges, the response of beams including the observed crack propagations, beam deflection, modes of failure, capacity enhancement at service and ultimate and the amount of moment redistribution are measured, presented and discussed. The study is appropriate in the sense that it covers the more commonly occurring two span beams instead of the simply supported beams investigated by others. The experiments reconfirmed the finding of others that proper installation of composite strengthening system is most important in the quality of the bond which is essential for the internal transfer of forces. It was also found that for the tested two span continuous beams, the capacity enhancement is more pronounced at the serviceability level than the ultimate. This is an important finding as the design of these beams is mostly governed by the serviceability limit state signifying the appropriateness of the suggested strengthening method. The paper provides quantitative data on the amount of this capacity enhancement.

Reliability analysis of circular tunnel with consideration of the strength limit state

Ghasemi, Seyed Hooman,Nowak, Andrzej S. Techno-Press 2018 Geomechanics & engineering Vol.15 No.3

Probability-based design codes have been developed to sufficiently confirm the safety level of structures. One of the most acceptable probability-based approaches is Load Resistance Factor Design (LRFD), which measures the safety level of the structures in terms of the reliability index. The main contribution of this paper is to calibrate the load and resistance factors of the design code for tunnels. The load and resistance factors are calculated using the available statistical models and probability-based procedures. The major steps include selection of representative structures, consideration of the limit state functions, calculation of reliability for the selected structures, selection of the target reliability index and calculation of load factors and resistance factors. The load and resistance models are reviewed. Statistical models of resistance (load carrying capacity) are summarized for strength limit state in bending, shear and compression. The reliability indices are calculated for several segments of a selected circular tunnel designed according to the tunnel manual report (Tunnel Manual). The novelty of this paper is the selection of the target reliability. In doing so, the uniform spectrum of reliability indices is proposed based on the probability paper. The final recommendation is proposed based on the closeness to the target reliability index.