Four phase hydrate equilibria of methane and carbon dioxide with heavy hydrate former compounds: Experimental measurements and thermodynamic modeling

Farzaneh Feyzi,Hamed Tavasoli 한국화학공학회 2016 Korean Journal of Chemical Engineering Vol.33 No.8

We experimentally investigated the hydrate dissociation condition for four phase hydrate (H)-aqueous liquid (LAq)-hydrocarbon rich liquid (LHC)-vapor (V) for the ternary systems of help gas-heavy hydrate former-water. Methane and carbon dioxide are known as help gases and benzene and cyclohexane are considered as heavy hydrate formers. The experimental data were generated using an isochoric pressure-search method. Two different equations of state (EOS) were employed to study the equilibrium phase behavior of ternary four phase systems. The EOSs considered are Valderama-Patel-Teja EOS combined with non-density dependent mixing rule (VPT+NDD) and Statistical Associating Fluid Theory EOS proposed by Huang and Radosz (SAFT-HR). The required binary interaction parameters (BIP) were obtained using vapor-liquid equilibrium (VLE) and liquid-liquid equilibrium (LLE) data. The hydrate phase was modeled by the modification of the solid solution theory of van der Waals and Platteeuw. To obtain reliable results, distortion of cages due to occupation of large molecules was considered. The Kihara parameters of cyclohexane were adjusted to hydrate dissociation data. Model calculations for hydrate forming conditions were found to be in satisfactory agreement with the newly reported data in this work and literature data.

Tetracycline degradation using combined system of dielectric barrier discharge air plasma and zeolites synthesized at different Na2O/SiO2 ratios

Leila Feyzi,Nader Rahemi,Somaiyeh Allahyari 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.104 No.-

In this work, a combination of synthesized zeolite with a Dielectric Barrier Discharge (DBD) air plasmareactor was applied for the removal of tetracycline (TC) from effluents. The zeolites with differentNa2O/SiO2 ratios were synthesized and inserted in a DBD reactor. The as-prepared zeolites were characterizedby FTIR, SEM, BET, EDX, XRD, and TEM. The XRD results showed that the P-type zeolite turned toY-type zeolite with an increasing Na2/SiO2 ratio from 0.5 to 1.5 and 2.5. The TC degradation experimentsindicated that 79.1% of the initial TC was removed from the solution by the hybrid plasma- zeolite (Na2O/SiO2 ratio of 0.5) system after 45 min. The plasma in synergy with zeolite caused the changing amount oflong-life oxidants in the system and converted it to higher reactive species. The combined system couldreduce around 17 and 10% of the total organic carbon (TOC) and chemical oxygen demand (COD) morethan the sole DBD system, respectively. Losing just 8% of the initial efficiency of the hybrid system afterfour successive runs revealed the stability of the proposed system. The radical trapping experimentmethod indicated that the role of OH in the TC degradation was more critical than that of O2.

Catalytic performance and characterization of cobalt-nickel nano catalysts for CO hydrogenation

Mostafa Feyzi,Arash Babakhanian,Mohammad Bagher Gholivand 한국화학공학회 2014 Korean Journal of Chemical Engineering Vol.31 No.1

A series of Co-Ni nano catalysts were prepared by co-precipitation method. We investigated the effect of Co/Ni molar ratios precipitate and calcination conditions on the catalytic performance of cobalt nickel catalysts for Fisher-Tropsch synthesis (FTS). The catalyst containing 90%Co/10%Ni was found to be optimal for the conversion of synthesis gas to light olefins. The activity and selectivity of the optimal catalyst were studied in different operational conditions. The results show that the best operational conditions are the H2/CO=2/1 molar feed ratio at 310 oC and GHSV=1,200 h−1 under 5 bar of pressure. The prepared catalysts were characterized by powder X-ray diffraction (XRD),N2 adsorption-desorption measurements such as BET and BJH methods, transmission electron microscopy (TEM) and thermal gravimetric analysis (TGA).

Therapeutic Difficulty in a Case of Supratentorial Primitive Neuroectodermal Tumor Diagnosed during Pregnancy

Sarica, Feyzi Birol,Tufan, Kadir,Sen, Orhan,Erdogan, Bulent The Korean Neurosurgical Society 2009 Journal of Korean neurosurgical society Vol.45 No.1

We report a supratentorial primitive neuroectodermal tumor (sPNET) in 17-year-old primipara in the second trimester her pregnancy. Magnetic resonance imaging revealed a left frontoparietal mass with solid and cystic component. Gross-total resection was achieved via a left frontoparietal craniotomy. It was decided to suspend the radiotherapy and chemotherapy until the 30 weeks of gestation. But, a sudden uncal herniation was developed due to the reccurrence of the tumor and bleeding into the tumor at the 25 weeks of gestation and the patient died after urgent decompressive surgery. sPNETs is an extremely rare brain tumor in pregnancy and only two cases were reported in the literature to date. There is no universally agreed treatment protocol for sPNETs during pregnancy and a multidisciplinary approach is required in treatment. In the present study, the clinical, histopathological features and therapeutical difficulties of sPNETs diagnosed during pregnancy was discussed with the literature review.

A novel Ce-MOF/PES mixed matrix membrane; synthesis, characterization and antifouling evaluation

Farrokh Mohammadnezhad,Mostafa Feyzi,Sirus Zinadini 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.71 No.-

A new polyethersulfone (PES) nanofiltration membrane, modified with nanocrystalline Ce(III)metal–organic framework (MOF), was produced via the phase inversion method and characterizedusing scanning electron microscopy (SEM), atomic force microscopy (AFM), water contact angle andporosity measurements. The morphology and performance of these membranes were investigated interms of pure waterflux, water contact angle, fouling parameters and dye removal. Modified PESmembranes showed an increase in the pure waterflux relative to the bare membrane. The changes insublayer and skin layer of modified membranes and also increased pore size and porosity is obvious fromthe SEM images of PES membranes porosity measurements. Moreover, the surface hydrophilicity of theMOF embedded membranes was improved due to the tendency of water to the membrane surface. Theantifouling properties of the membranes were evaluated by powder milk solution and measuring thefluxrecovery ratio (FRR). The results revealed the modified membrane with 0.5 wt.% of MOF nanoparticle(NPs) had the best antifouling property and also the highest porosity and waterflux. Nanofiltrationperformance of membranes was appraised by probing of the retention of Direct Red 16. The resultshowed that all the modified membranes have a higher dye rejection capacity than the bare PESmembrane.

Development of electrolyte SAFT-HR equation of state for single electrolyte solutions

Azam Najafloo,Farzaneh Feyzi,Ali Taghi Zoghi 한국화학공학회 2014 Korean Journal of Chemical Engineering Vol.31 No.12

The explicit version of the mean spherical approximation (MSA) is added to the SAFT-HR equation ofstate (EoS) to model aqueous alkali halide solutions. The proposed electrolyte equation of state (eEoS) has two par-ameters per each ion. Two methods are in common use for calculating ion parameters: ion-based and salt-based. Inthis work, the electrolyte parameters are obtained for 61 single electrolyte solutions using salt-based method. Usingthis approach, mean ionic activity coefficients of the 61 aqueous electrolyte systems were modeled with overall averageabsolute relative percent deviation (AAD%) of 3.91. Also, for testing the ability of the model in terms of ionic par-ameters, six salts (NaCl, NaBr, NaI, KCl, KBr and KI) were studied using ion-based method. The liquid densities, os-motic coefficients and salt mean ionic activity coefficients of 6 aqueous electrolyte solutions were modeled with overallAAD% of 0.68, 2.28 and 0.96, respectively.

Tectonic Geomorphology of the North Anatolian Fault Zone in the Lake Sapanca Basin (Eastern Marmara Region, Turkey)

Alper Gürbüz,Ömer Feyzi Gürer 한국지질과학협의회 2008 Geosciences Journal Vol.12 No.3

In this study the spatial variations of the Plio-Quaternary tectonic activity and deformation of different fault segments of the North Anatolian Fault Zone (NAFZ) in the eastern Marmara region around Lake Sapanca, are assessed using geomorphic, morphometric and bathymetric approaches. Lake Sapanca is an E-W-trending structure located in the zmit-Sapanca Corridor. This region is bounded to the north and to the south by the series of mountain ranges. Geomorphic and morphometric data provide evidence for variations between the two mountain front faults regarding levels of tectonic activity. These studies suggest a relatively high degree of tectonic activity along the Sapanca front in the south, in contrast with a low degree of tectonic activity along the E me front in the north of the study area. This pattern is also consistent with field evidence and seismic data of the study area. Bathymetric profiles of the lake show that the lake basin consists of different fault segments that slipped in the 1999 Kocaeli earthquake. All these data suggest that the zmit-Sapanca Corridor is an asymmetric pull-apart basin associated with displacement along the NAFZ in the Late Pliocene. Lake Sapanca also occurs as a pull-apart basin created by the cross-basin fault of the asymmetric pull-apart basin in the Middle Pleistocene.

Analytical solution of temperature distribution in resistance spot welding

Soran Hassanifard,Mohsen Feyzi 대한기계학회 2015 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.29 No.2

In this study, an analytical model based on integral transformations was developed to predict nugget diameters in resistance spot weldingof 1.5 mm thick 5083-O aluminum alloy sheets. Welding time was fixed at six cycles. However, welding current and electrode pressurewere changed; experiments were carried out for both situations. First, the effect of contact resistance on nugget diameters was studied. During the welding process, three electrode forces were selected at 2500, 3000, and 3500 N, and the welding current was fixed at20 kA. Second, the effect of welding current on the nugget diameter was investigated. In the investigation, the electrode force was fixedat 3000 N, and the welding current was varied at 20, 25, and 30 kA. To improve accuracy, a correction factor to thermal expansion wasconsidered. Finally, the effect of welding time on thermal history was investigated theoretically.

On Some Spaces Isomorphic to the Space of Absolutely q-summable Double Sequences

Capan, Husamettin,Basar, Feyzi Department of Mathematics 2018 Kyungpook mathematical journal Vol.58 No.2

Let 0 < q < ${\infty}$. In this study, we introduce the spaces ${\mathcal{BV}}_q$ and ${\mathcal{LS}}_q$ of q-bounded variation double sequences and q-summable double series as the domain of four-dimensional backward difference matrix ${\Delta}$ and summation matrix S in the space ${\mathcal{L}}_q$ of absolutely q-summable double sequences, respectively. Also, we determine their ${\alpha}$- and ${\beta}-duals$ and give the characterizations of some classes of four-dimensional matrix transformations in the case 0 < q ${\leq}$ 1.

Incidental gallbladder cancer: a retrospective clinical study of 40 cases

Merih Altiok,Hanife Gülnihal Özdemir,Feyzi Kurt,Mehmet Onur Gul,Serdar Gumus 대한외과학회 2022 Annals of Surgical Treatment and Research(ASRT) Vol.102 No.4

Purpose: Cholecystectomy is one of the most common surgeries today due to gallbladder diseases. The most prevalent malignancy of the biliary tract is gallbladder cancer. We aimed to discuss the results of our patients who underwent cholecystectomy for benign reasons in our clinic and who had gallbladder cancer due to pathology. Methods: The results of cholecystectomy performed in General Surgery Clinic of Seyhan Government Hospital were evaluated. Cases diagnosed as gallbladder as a result of histopathological examination were included. Preoperative ultrasonography, laboratory findings, and postoperative pathology results of the patients were reviewed retrospectively. The pathologist repeated histopathological evaluations. Results: Between 2010 and 2019, incidental gallbladder cancer (IGBC) was detected in 40 patients (0.3%) in 11,680 cholecystectomy operations. Of the patients diagnosed with IGBC, 14 (35.0%) were T1a, 11 (27.5%) were T1b, 11 (27.5%) were T2, and 4 (10.0%) were T3. T4 tumor was not seen in any patient. Three patients who were T1b at initial evaluation were identified as T2 at evaluation for the study. The pathology results of 37 patients (92.5%) were adenocarcinoma, 2 (5.0%) were adenosquamous type, and 1 (0.5%) was squamous cell carcinoma. Conclusion: There has been a remarkable increase in the number of IGBCs over the past 20 years. Appropriate staging and histopathological evaluation are essential in guiding the surgeon’s operation. It is crucial to accurately determine the T stage, the most influential parameter on patient survival and residual recurrences. The distinction between pathologic (p) T1a and pT1b should be made carefully. Surgery is the only potentially curative method.