A novel ternary Pd-GO/N-doped TiO2 hierarchical visible-light sensitive photocatalyst for nanocomposite membrane

Hossein Mahdavi,Mahdi Rezaei,Leila Ahmadian-Alam,Mostafa Mohammadpour Amini 한국화학공학회 2020 Korean Journal of Chemical Engineering Vol.37 No.6

We investigated the visible-light sensitive photocatalytic ability of a designed ternary Pd-GO/TiON nanocomposite for use as an effective photocatalyst in membranes. We succeeded in synthesizing the TiO2-based photocatalyst for Suzuki coupling reaction and application of this photocatalyst for fabricating high performance photocatalytic membrane. In this regard, palladium metal as a complementary metal in combination with N-doped TiO2 (TiON) and graphene oxide (GO) nanosheets was utilized to synthesize the upgraded version of the visible light sensitive nanocomposite photocatalyst. The synthesis of Pd-GO/TiON hierarchical nanostructure was confirmed by detecting Ti, Pd, C, O and N elements by X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray (EDX) and EDX mapping analysis. Then, a series of PVDF-based photocatalytic nanocomposite membranes (PhNMs) filled with Pd-GO/TiON was fabricated. Evaluating the yield of Pd-GO/TiON photocatalyst was around 99% and 70% for heterogeneous system and the prepared PhNM containing 3% Pd-GO/TiON, respectively. Although, yield of Pd-GO/TiON photocatalyst in membrane is not comparable with the high yield reported by other researchers in heterogeneous system; however, it can be considered as a valuable result because of the importance of photocatalytic reactions and the environmental advantages of membrane technology. Furthermore, various analyses were also performed to study the synthesized photocatalysts and the prepared photocatalytic membranes, including thermogravimetric analysis (TGA), scanning electron microscopy (SEM), X-ray powder diffraction (XRD) and diffuse reflectance spectrophotometry (DRS).

Effects of Simulated In-Transit Vibration on the Vase Life and Post-Harvest Characteristics of Cut Rose Flowers

Hossein Alizadeh Pouri,Abdolhossein Rezaei Nejad,Feizollah Shahbazi 한국원예학회 2017 Horticulture, Environment, and Biotechnology Vol.58 No.1

We examined whether exposure to vibration during transport affects the quality of cut roses. Using alaboratory vibration simulator, in-transit vibration of 7.5 or 10 Hz was applied to two cut rose cultivars (‘Polar Star’and ‘Revival’) at three positions within a compartmented storage bin (top, middle, and bottom) for 10 or 15 min. Post-harvest characteristics of the cut flowers were measured in a test room. We observed that in both cultivars,vibration significantly reduced vase life (VL), decreased relative fresh weight (RFW), and increased flower openingrate (FOR). No significant differences were observed between vibration frequencies, positions, or durations in ‘PolarStar’ with respect to VL. Furthermore, we applied a simulated vibration of 10 Hz to three cut rose cultivars (‘PolarStar’, ‘Magic Red’, and ‘Full House’). We observed that ‘Polar Star’ was more sensitive to vibration damage thanthe other two cultivars. Pulse treatments coupled with the exogenous application of silver thiosulfate (STS), an ethyleneaction inhibitor, were applied to ‘Polar Star’ before and after vibration. Independent of the concentration used andtime of application, STS significantly decreased FOR, water uptake, water loss, and increased RFW. However, only1 mM STS applied before vibration extended VL compared to non-vibrated control VL. Thus, vibration duringtransport could shorten the VL of cut rose flowers. The amount of vibration damage in cut rose flowers is cultivardependent. Taken together, our data suggest that ethylene underlies the negative impact of vibration on post-harvestcharacteristics of cut rose flowers. Application of ethylene action inhibitors before transit could reduce or prevent thevibration effects on the post-harvest quality of sensitive cut rose cultivars.

Effect of interfering ions on phosphate removal from aqueous media using magnesium oxide@ferric molybdate nanocomposite

Hossein Esmaeili,Rauf Foroutan,Dariush Jafari,Mohammad Aghil Rezaei 한국화학공학회 2020 Korean Journal of Chemical Engineering Vol.37 No.5

The removal efficiency of phosphate ion from aqueous media using magnesium oxide/iron molybdate (MgO/Fe2(MoO4)3) nanocomposite was investigated. MgO nanoparticles were chemically modified by ferric molybdate. Then, the structure and morphology of the nanocomposite was completely investigated using different analyses such as SEM, EDX/Map, FTIR, XRD, TGA, BET, and TEM. The TEM analysis demonstrated that the particles in the mentioned nano-composite were on a nanoscale. BET analysis proved that the nanocomposite was mesoporous with mean pore size of 9.4 nm. The sorption outcomes demonstrated that the highest phosphate sorption yield was achieved at 98.38%, exhibiting remarkable sorption efficiency. Carbonate ions showed to have the highest interfering impact compared to sulfate and nitrate ions, since phosphate ion removal efficiency decreased significantly when carbonate and phosphate ions were simultaneously available in the solution. The thermodynamic studies demonstrated that the current sorption process was spontaneous, possible, and exothermic. The sorption equilibrium investigation showed that the Freundlich isotherm model can describe the adsorption of phosphate ion better than can the Langmuir model, and the maximum sorption capacity was obtained as 30.21mg/g. Additionally, the adsorbent was successfully regenerated four times and was able to perform the sorption and desorption process well.

Grid-Connected Photovoltaic System Based on a Cascaded H-Bridge Inverter

Rezaei, Mohammad-Ali,Iman-Eini, Hossein,Farhangi, Shahrokh The Korean Institute of Power Electronics 2012 JOURNAL OF POWER ELECTRONICS Vol.12 No.4

In this paper a single-phase Cascaded H-Bridge (CHB) inverter for photovoltaic (PV) applications is presented. Based on the presented mathematical analysis, a novel controller is introduced which adjusts the inverter power factor (PF) and manipulates the distribution of the reactive power between the cells to enhance the operating range of the CHB inverter. The adopted control strategy enables tracking of the maximum power point (MPP) of distinct PV strings and allows independent control of the dc-link voltages. The proposed controller also enables the inverter to operate under heavily unbalanced PV conditions. The performance of the CHB inverter and the proposed controllers are evaluated in the PSCAD/EMTDC environment. A seven-level CHB-based grid connected laboratory prototype is also utilized to verify the system performance.

The Effect of Crocus sativus Extract on Human Lymphocytes’ Cytokines and T Helper 2/T Helper 1 Balance

Mohammad Hossein Boskabady,Seyedh Masoumeh Seyedhosseini Tamijani,Houshang Rafatpanah,Abadolrahim Rezaei,Azam Alavinejad 한국식품영양과학회 2011 Journal of medicinal food Vol.14 No.12

The effects of macerated extracts of Crocus sativus (Family Iridaceae) (saffron) on cell viability and cytokine release of stimulated peripheral blood mononuclear cells by phytohemagglutinin (PHA) and nonstimulated cells were examined. The effects of three concentrations of macerated extract, dexamethasone, and saline on cell viability and production of cytokines, including interleukin (IL)-4, IL-10, andinterferon-γ (IFN-γ) were evaluated. In cells stimulated with PHA,different concentrations of the extract significantly inhibited cell viability of lymphocytes (P < .001 for all concentrations). High concentrations of the extract (500 ㎍/mL) also inhibited secretion of IFN-γ in stimulated cells and IL-10 secretion in both stimulated and nonstimulated cells (P < .05 for all cases). The effects of high and low concentrations of the extract (500 and 50 ㎍/mL, respectively) on IL-4 secretion were lower than that of dexamethasone (P < .05 to P < .001). The extract showed a stimulatory effect on IFN-γ and IL-4 secretion in nonstimulated cells. The ratios of IFN-γ to IL-4 in the presence of all concentrations of saffron on stimulated cells were significantly higher than for the control group (P < .05 to P < .01). These results indicated that the extract of saffron leads to increased ratio of IFN-γ to IL-4.

The effect of promoters on the CO2 reforming activity and coke formation of nanocrystalline Ni/Al2O3 catalysts prepared by microemulsion method

Mehran Rezaei,Mohammad Hossein Aboonasr Shiraz,Fereshteh Meshkani 한국화학공학회 2016 Korean Journal of Chemical Engineering Vol.33 No.12

Mesoporous nanocrystalline nickel-alumina promoted catalysts with high surface area were prepared by microemulsion (ME) method and employed in dry reforming of methane reaction. The catalysts were characterized by X-ray diffraction (XRD), Brunauer-Emmett-Teller surface area analysis (BET), temperature programmed reduction (TPR) and temperature programmed oxidation (TPO) techniques. The results showed that the prepared catalysts had high porosity with great surface area and small crystallite size. Among the K2O, MgO, CaO and BaO promoters, the MgO promoter showed considerable effect on catalytic performance and coke suppression of catalyst.

Brief communication : Bloody Diarrhea as a Presentation Manifestation of Familial Mediterranean Fever in a Patient with Compound Heterozygote Mutations of the MEFV Gene

( Gholam Hossein Fallahi ),( Nima Rezaei ),( Nooshin Sadjadei ) 대한소화기학회 2013 Gut and Liver Vol.7 No.4

Familial Mediterranean fever (FMF) is a hereditary autoinflammatory disease characterized by episodic fever and inflammatory polyserositis, which could lead to a variety of manifestations, including recurrent abdominal pain. Herein, a 12-year-old boy who has suffered from fever and bloody diarrhea since early childhood is described. All structural and underlying disorders leading to bleeding were excluded. Genetic studies indicated compound heterozygote mutations of M680I/R761H in the MEFV gene, which confirmed the diagnosis of FMF. Therefore, treatment with colchicine was started, which led to symptom relief. As gastrointestinal manifestations appear to be the main features of FMF, bloody diarrhea could also be considered an initial symptom of FMF. (Gut Liver 2013; 7:497-499)

Amphiphilic A3B3 miktoarm star polymer: synthesis and micellization study by fluorometry, TEM and DLS techniques

Abbas Rezaei,Faezeh Aminian,Hossein Behniafar 한국고분자학회 2023 Macromolecular Research Vol.31 No.9

A new amphiphilic six-armed A3B3-type miktoarm star polymer was synthesized starting from a triazidohydrin as the core. First, three hydrophobic arms of polycaprolactone were formed on the core through ring-opening polymerization (core-first method). Next, presynthesized PEG-based hydrophilic arms were attached to the previous structure using click chemistry (arm-first method). In the vicinity of the junction of the hydrophilic arms to the core, bio-reducible disulfide bonds were embedded. The prepared star polymer was characterized by elemental analysis and spectroscopic techniques (FT-IR and H-NMR). Using transmission electron microscopy (TEM) it was found that the amphiphilic macromolecules at concentrations higher than critical micelle concentration (CMC) formed spherical micelles with an average diameter below 100 nm. The CMC of the synthesized amphiphilic polymer in aqueous solution was determined by fluorometric method via examining the emission spectra of an organic probe. Thus, it was measured to be 1.76 × 10–3 mg/mL (3.90 × 10–7 M). In addition, dynamic light scattering measurements indicated that the spherical micelles had a mean hydrodynamic diameter (DH) of ~ 70 nm and polydispersity index of 0.17.

Slow Coronary Flow Phenomenon and Increased Platelet Volume Indices

Mir Hossein Seyyed-Mohammadzad,Kamal Khademvatani,Abdollah Kerachian,Ramin Eskandari,Yousef Rezaei 대한심장학회 2014 Korean Circulation Journal Vol.44 No.6

Background and Objectives: We sought to determine the relationship between mean platelet volume (MPV), platelet distribution width (PDW), and platelet larger cell ratio (P-LCR) with slow coronary flow (SCF). Subjects and Methods: Eighty participants who underwent coronary angiography were divided into two groups, 50 participants with SCF as case group, and 30 with normal coronary flow (NCF) as control group. Baseline characteristics and laboratory data were collected before angiography. Results: Platelet volume indices MPV (10.8±1.2 fL), PDW (14.5±2.2 fL), and P-LCR (30.5±8.1%) in the SCF group were significantly (p<0.05) higher than those (10.1±0.9 fL, 13.2±1.8 fL, and 26.8±6.8%, respectively) in the NCF group. The patients with three SCF arteries had significantly higher platelet volume indices compared to those with NCF arteries; however, the patients with one SCF artery did not. Based on linear regression model, MPV, PDW, and P-LCR were independent predictors of mean infarction frame counting (TFC). In multivariate analysis, MPV {odds ratio (OR)=32.393, 95% confidence interval (CI)=1.189–882.606, p=0.039} and P-LCR (OR=0.566, 95% CI=0.330– 0.937, p=0.028) were independent predictors of SCF. Conclusion: Platelet volume indices MPV, PDW, and P-LCR were associated with both the presence and extent of SCF.

Analysis and Optimization of Permanent Magnet Dimensions in Electrodynamic Suspension Systems

Hasanzadeh, Saeed,Rezaei, Hossein,Qiyassi, Ehsan The Korean Institute of Electrical Engineers 2018 Journal of Electrical Engineering & Technology Vol.13 No.1

In this paper, analytical modeling of lift and drag forces in permanent magnet electrodynamic suspension systems (PM EDSs) are presented. After studying the impacts of PM dimensions on the permanent magnetic field and developed lift force, it is indicated that there is an optimum PM length in a specified thickness for a maximum lift force. Therefore, the optimum PM length for achieving maximum lift force is obtained. Afterward, an objective design optimization is proposed to increase the lift force and to decrease the material cost of the system by using Genetic Algorithm. The results confirm that the required values of the lift force can be achieved; while, reducing the system material cost. Finite Element Analysis (FEA) and experimental tests are carried out to evaluate the effectiveness of the PM EDS system model and the proposed optimization method. Finally, a number of design guidelines are extracted.