Polyurethane/Poly(vinyl alcohol) Blend Membranes for Gas Separation

Hemmat Shirvani,Morteza Sadeghi,Hajar Taheri Afarani,Rouhollah Bagheri 한국섬유공학회 2018 Fibers and polymers Vol.19 No.5

This Study involves preparation and characterization of polyurethane (PU) and polyurethane/poly(vinyl alcohol) (PU/PVA) blend membranes for gas separation. PU was synthesized by two step polymerization based on isophorone diisocyanate (IPDI), 1,4-butanediamine (BDA), polytetramethylene glycol (PTMG) in the mole ratio of 3:2:1. The prepared blend membranes were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray Diffraction (XRD), and scanning electron microscopy (SEM). The effects of molecular weight of PVA, and blend composition on the gas transport properties of N2, O2, CO2 and CH4 were investigated. Obtained results show that the permeability of gases decreased in blend membranes by poly(vinyl alcohol) (PVA) molecular weights while their gas selectivity enhanced. Comparison of the gas separation performance of the prepared membranes to Robeson upper bound, reveal the enhancement of membrane performance by introducing PVA in PU matrix.

Experimental, Price-Performance and Artificial Neural Network (ANN) Analysis of MWCNT-CuO/ Water-EG (50-50) Nanofluid as a Coolant/Antifreeze Working Fluid

Hemmat Esfe Mohammad,Togharie Davood 한국화학공학회 2024 Korean Journal of Chemical Engineering Vol.41 No.6

In this study, the thermal conductivity (TC) of CuO–MWCNT/water–EG hybrid nanofl uid (NF) was experimentally measured. The experiments were conducted at temperatures ranging from 30 to 50 °C, and SVFs of 0.02–1%. The results indicate that the relative TC increases with any increase in temperature and SVF. As the SVF of nanoparticles increases, the relative TC increases more steeply. To have an advantageous NF price–performance, the analysis of this NF was conducted and compared with NFs enriched by single nanoparticles like COOH–MWCNT and CuO nanoparticles. An equation was provided to determine the thermal performance of the NF versus its price. This applied equation shows the thermal performance of the NF versus its prime cost and allows users to select the best options in terms of price and performance for application in various pieces of equipment. According to results for hybrid suspension, fl uids with SVFs of lower than 0.25% and also 1% are the advantageous ones. Also, NFs samples that only contains CuO nanoparticles are not economical in any SVFs. About the NFs containing MWCNT nanoparticles, no SVF was economic except the highest SVF because of its sharp TC enhancement. On the other hand, empirical data were modeled and estimated using the artifi cial neural network (ANN) and the empirical correlation. The modeling results show that the ANN was more accurate in estimating the experimental results.

Study of Rheological Behavior, Economic Performance and Development of a Model for MWCNT-ZnO (30:70)/10W40 Hybrid Nanofluid Using Response Surface Methodology

Hemmat Esfe Mohammad,Motallebi Sayyid Majid,Esfandeh Saeed,Toghraie Davood 한국화학공학회 2024 Korean Journal of Chemical Engineering Vol.41 No.3

The aim of this article is an empirical investigation of the MWCNT and ZnO (30:70)/10W40 HNF against SR, SVF, and T. In this study, the nanoparticles (NPs) are examined with SVF = 0.05%-1% and T = 5–55 °C. After adding NPs to 10W40 engine oil, non-Newtonian behavior is observed. Optimizing the viscosity behavior of NF is another goal of this study, which has been achieved with the special combination of NPs and adding them to the base fl uid. The present introduced NF has given a more controlled viscosity and a cheaper price in competition with the other three reviewed NFs available in the literature. To predict the viscosity, RSM is used, which is based on the experimental results. The margin of deviation (MOD) is less than ±5%. Also, the sensitivity analysis in diff erent SVFs and temperatures is analyzed separately.

Numerical study of laminar-forced convection of Al2O3 -water nanofluids between two parallel plates

M. Hemmat Esfe,A. A. Abbasian Arani,T. Azizi,S. H. Mousavi,S. Wongwises 대한기계학회 2017 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.31 No.2

Laminar-forced convection of Al 2 O 3 -water nanofluid between two parallel plates was studied numerically. The channel walls were assumed to be isothermal. The effective viscosity and thermal conductivity of nanofluid were considered as variables, and the effects of applying a variable properties model were investigatedby using two relatively new models. The numerical results were compared to the results obtained from a previous non-variable properties model. Also, the effects of nanoparticle size on the flow and heat transfer within the channel were investigated. The study was carried out using Reynolds numbers between 100-1000, nanoparticle diameters in the 15-75 nm range, and nanoparticle volume fractions in the range 0.01-0.05 nm. The numerical results show that using nanofluid could enhance heat transfer by up to 35 %, compared to the base fluid. In addition, reducing the nanoparticle diameter can enhance heat transfer by up to 15.9 %.

Experimental study rheological behavior of MWCNT (10%)-TiO2 (90%)/SAE40 hybrid nano-lubricants (HNLs) post-processing of the results with response surface methodology (RSM)

Mohammad Hemmat Esfe,Soheyl Alidoust,Saeed Esfandeh,Davood Toghraie,Erfan Mohammadnejad Ardeshiri 한국화학공학회 2023 Korean Journal of Chemical Engineering Vol.40 No.4

In this study, which was approached with an industrial approach, for the first time, the rheological behavior of hybrid nano-lubricants (HNLs) with the formulation MWCNT (10%)-TiO2 (90%)/SAE40 was investigated experimentally, statistically and numerically. Nano-solution study conditions were performed in six solid volume fractions (=0.0625% to 1%) and a temperature range of T=25 to 50 °C. Quantitative statistics of laboratory studies show that the maximum and minimum viscosity of HNLs relative to the base oil increase and decrease by 29.6%, −13.40%, respectively. To predict the experimental data, to provide a correlation relationship and to establish a relationship between the target response and the effective variables, response surface methodology (RSM) with a three-point model and coefficient of determination 0.9986 was used.

Modeling and optimization of dynamic viscosity of oil-based nanofluids containing alumina particles and carbon nanotubes by response surface methodology (RSM)

Mohammad Hemmat Esfe,Sayyid Majid Motallebi,Davood Toghraie 한국화학공학회 2022 Korean Journal of Chemical Engineering Vol.39 No.10

The dynamic viscosity of MWCNT-Al2O3 (40 : 60)/SAE50 nanofluid (NF) is investigated. NF viscosity modeling is also performed using the response surface methodology (RSM). Several different models are proposed, including modified and unmodified cubic, quartic and fifth models, and the best modeling is selected using the parameters R2, Adjusted R2, Predicted R2 and Square root of the residual mean square (Std. Dev.). The results show that the fifth-order model has values of 0.9997, 0.9997, 0.9996 and 2.39 for R2, Adjusted R2, Predicted R2 and Std. Dev. parameters, respectively, which indicates high accuracy of modeling. Using the perturbation diagram, it was found that among the parameters of temperature, solid volume fraction () and shear rate (), the temperature parameter has the greatest effect on the dynamic viscosity of NF. The trend of changes in viscosity also shows that  and  have little effect on viscosity. Due to the importance of low viscosity in fluid flow and pumping, the optimal values of NF viscosity are presented, including dynamic viscosity equal to 108.092 cP in  =0.063 and T=49.998 oC and  =7,866.7786 s1.

KOREA AND THE MING TRIBUTE SYSTEM IN KHATAYI’S BOOK OF CHINA

KAVEH L. HEMMAT 계명대학교 한국학연구원 2018 Acta Koreana Vol.21 No.1

The Book of China (Khataynameh), a description of China written in 1516, in Persian, for the Ottoman court by a Central Asian merchant, includes a brief section on Korea in the chapter on the twelve provinces of China, which describes habitual interaction between Muslim and Korean merchants. The brevity of this notice and the mis-categorization of Korea as a province of the Ming state might appear to indicate that the author was largely uninformed about Korea and its political relationship to China. However, the didactic and political nature of the text, which presented a utopian image of China as a model to be emulated by a nascent Ottoman Empire, as well as the author’s more general familiarity with East Asian cultural and political circumstances, suggest that his subsuming of the Chosŏn state into the Ming empire was more an ideologically-motivated choice than a manifestation of negligence or ignorance. The image of economic and military power conveyed through the Ming tribute system formed the basis of a political ideal of universal empire; conveying this ideal was the principal goal of the text. The author’s fealty to an idealized formulation of imperial authority echoes the Chosŏn elite’s own strategy for balancing political independence with material support and cooperation from the Ming, by adhering closely to a Sinocentric Neo-Confucian ideology. The Book of China thus attests to, and constitutes part of, a global process of political communication that connected the Ottoman Empire with Central Asia, China, and Korea.

Song Blue and White Porcelain on the Silk Road. Adam T. Kessler

( Kaveh Louis Hemmat ) 계명대학교 실크로드연구원 2017 Acta Via Serica Vol.2 No.1

Correlation and thermal conductivity sensitivity analysis of ternary hybrid nanofluids containing CuO and TiO2 nanoparticles and multi-walled carbon nanotubes

Esfe Mohammad Hemmat,Alidoust Soheyl,Toghraie Davood 한국화학공학회 2023 Korean Journal of Chemical Engineering Vol.40 No.9

The use of substandard nanofluids (NFs) in various industries causes the depreciation of industrial parts and shortens the life of the parts. Therefore, the researchers in this study will help to improve the performance of industrial equipment by preparing and examining a special hybrid nanofluid (HNF). The current research is divided into two experimental and theoretical parts. First, a ternary hybrid nanofluid (THNF) with three nanoparticles (NPs) CuO, MWCNT and TiO2 with specific ratios and solid volume fraction (SVF) in water was prepared and produced. Then, the thermal conductivity (TC) of the produced nanofluid (NF) is measured by KD2 pro at different temperatures and SVFs. The results show that temperature and SVF are directly related to thermal conductivity enhancement (TCE). The maximum TC of the desired THNF is equal to 35.60% at SVF=1.65% and T=50°C. In the theory part, using the response surface method (RSM), a very accurate correlation relationship R2=0.9986 is provided. Also, the sensitivity of relative thermal conductivity (RTC) to changes of +10% SVF is presented, and the maximum deviation for the studied THNF is equal to 0.95%.

Cost and Efficiency Optimizations of ZnO/EG Nanofluids Using Non-dominated Sorting Genetic Algorithm Coupled with a Statistical Method

Esfe Mohammad Hemmat,Hajmohammad Hadi,Motallebi Seyed Majid,Toghraie Davood 한국화학공학회 2024 Korean Journal of Chemical Engineering Vol.41 No.1

In this study, optimization of ZnO/EG nanofl uids was investigated to increase effi ciency and reduce costs. To determine the effi ciency of nanofl uid, the defi nition of Mouromtseff number was used. The cost of nanofl uid in terms of the volume fraction of nanoparticles ( φ ) was determined. Then, Mouromtseff functions and costs were calculated by response surface methodology (RSM) with regression up to 96%. To determine the minimum cost and maximum effi ciency in terms of Mouromtseff number, a non-dominated sorting genetic algorithm (NSGA II) which is powerful in achieving optimal response was employed. In the end, the Pareto front, optimal values of Mouromtseff , and the minimum corresponding cost were obtained. Also, for achieving an optimal pattern of minimum cost in terms of maximum thermal effi ciency, a suitable correlation was presented. The results show that to achieve maximum thermal effi ciency, the minimum cost is $ 360 per liter and also the minimum cost to achieve the optimal effi ciency coeffi cient is in φ = 0.5%. Nanofl uid optimization can also reduce nanofl uid costs by up to 10%.