Spray Uniformity Dependence on the Fuel Temperature from a Pressure Swirl Nozzle

Reza Alidoost Dafsari,Shahnaz Rezaee,Foad Vashahi,Jeekeun Lee 대한기계학회 2020 대한기계학회 춘추학술대회 Vol.2020 No.12

The quality of spray in combustion application is often described with the droplet mean size and spatial distribution. Drop size distribution is a prime factor for Combustion efficiency. An experimental study was conducted to investigate the effect of fuel temperature and accordingly physical properties on the droplet size uniformity factor. A Dantec phase Doppler anemometry PDPA system was employed to measure droplet size and flow visualization was carried out using a particle image velocimetry PIV system. The result shows a major effect of fuel temperature on the spray structure, hydraulic behavior, and spatial droplet distribution. Multiple size distribution functions were compared to find the best representation. Rosin-Rammler distribution shows the best fit to the experimental result. The q value of the Rosin- Rammler distribution as the uniformity factor was found to increase exponentially with increasing the fuel temperature. This observation can potentially help the enhancement of drop size distribution prediction accuracy.

Effect of Fuel Temperature on the Drop Size Distribution Function

Reza Alidoost Dafsari(레자알리두스트다프사리),Shahnaz Rezaee(샤나즈 레자이),Foad Vashahi(포아드 바샤이),Jeekeun Lee(이지근) 대한기계학회 2020 대한기계학회 춘추학술대회 Vol.2020 No.8

The spray structure and drop size distribution issuing from industrial nozzles are important for their application. In gas turbine combustion the uniformity and spatial distribution of the swirl spray initiates the combustion efficiency and product control. This study investigates the effect of injection pressure and physical properties of a commercial jet fuel (JET-A1) in a wide range with controlling the fuel temperature on the spatial structure of the spray. Furthermore, multiple droplet distribution functions suggested in the literature were examined to find the best applicable fit. Spray structure and droplet size measurement were carried out by applying laser diagnostic methods namely phase Doppler anemometry and Mie-scattering imaging method. The results showed with increasing both injection pressure and the fuel temperature and accordingly the decreasing the fuel viscosity, surface tension and density, enhances spray cone angle and atomization quality. Both studied parameters decreased the breakup length and consequently spray mean droplet size while widened the spray cone angle. Moreover, an in-depth attempt was made to find the accordance of q value of Rosin-Rammler distribution function to fuel temperature.

Behavior of exterior concrete beam-column joints reinforced with Shape Memory Alloy (SMA) bars

Hossein Rezaee Azariani,M. Reza Esfahani,Hashem Shariatmadar 국제구조공학회 2018 Steel and Composite Structures, An International J Vol.28 No.1

This research was conducted to study the behavior of exterior concrete beam-column joints with reinforced shape memory alloy (SMA) bars tested under cyclic loading. These bars benefit from superelastic behavior and can stand high loads without residual strains. The experimental part of the study, 8 specimens of exterior concrete beam-column joints were made and tested. Two different types of concrete with 30 and 45 MPa were used. Four specimens contained SMA bars and 4 specimens contained steel bars in beam-column joints. Furthermore, different transverse reinforcements were used in beams investigate the effects of concrete confinement. Specimens were tested under cyclic loading. Results show that SMA bars are capable of recentering to their original shape after standing large displacements. Due to the superelastic behavior of SMA bars, cracks at the joint core vanish under cyclic loading. As the cyclic loading increased, bending failure occurred in the beam outside the joint core. In the analytical parts of the study, specimens were simulated using the SeismoStruct software. Experimental and analytical results showed a satisfactory correlation. Plastic hinge length at the beam joint for specimens with SMA and steel bars was calculated by empirical equations, experimental and analytical results. It was shown that Paulay's and Priestley's equations are appropriate for concrete beam-column joints in both types of bars.

Optimization of process parameters for lipase-catalyzed synthesis of esteramines-based esterquats using wavelet neural network (WNN) in 2-liter bioreactor

Hamid Reza Fard Masoumi,Mahiran Basri,Anuar Kassim,Dzulkefly Kuang Abdullah,Yadollah Abdollahi,Siti Salwa Abd Gani,Malahat Rezaee 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.4

A wavelet neural network (WNN) based on the genetic algorithm (GA) was used in conjunction with an experimental design to optimize the enzymatic reaction conditions for the preparation of esteramines-based esterquats. A set of experiments was designed by central composite design to process modeling and statistically evaluate the findings. Five independent process variables, including enzyme amount, reaction time, reaction temperature, substrates molar ratio and agitation speed were studied under the given conditions designed by Design Expert software. All these show that the WNN has great potential ability in prediction of reaction conversion in lipase-catalyzed synthesis of products.

Relationship between university brand personality and student behavioral loyalty

Mohammad Reza Karimi Alavijeh,Morteza Rezaee,Vahid Hosseinabadi 한국교육개발원 2014 KEDI Journal of Educational Policy Vol.11 No.2

The brand personality and status of the university among other universities are important for encouraging students to choose a particular university. This study examines different dimensions of the university brand personality and the effect of brand personality on the student-university relationship, student loyalty, and the moderating role of ethics on the research model. The sample of the first study includes all the students of public universities of Tehran city, and for the second study all the students of University of Tehran. 403 and 399 completed surveys were collected for the first and second studies. The results of an exploratory factor analysis show that the university brand personality has six dimensions with twenty-two scales. The results of structural equation modeling show that the university brand personality has a positive and meaningful effect on student-university relations, the relationship between student and university and the likelihood of students recommending the university to others, and the willingness to continue academic study. Ethics has a moderating role, but its effect and intensity are not meaningful.

Charge reduction: an efficient strategy to reduce toxicity and increase the transfection efficiency of high molecular weight polyethylenimine

Mohammad Ramezani,Reza Kazemi Oskuee,Mehdi Rezaee,Leila Gholami,Mojtaba Seddighi Gildeh 한국약제학회 2019 Journal of Pharmaceutical Investigation Vol.49 No.1

With high potency in treatment of various diseases, gene therapy is mainly hindered by lack of safe and efficient gene delivery vectors. The current study was aimed to develop an efficient non-viral vector with adequate cytotoxicity. To this end, alkylcarboxylate chains (6C, 10C, 16C) were exploited to ameliorate the characteristics of PEI 750 kDa. Briefly, alkylcarboxylate chains with three different lengths (6C, 10C, 16C) were chemically grafted to the primary amine groups of PEI 750 kDa in three percentages (10, 50, and 100%). After evaluating the physicochemical properties of prepared vectors including surface charge, size, buffering capacity, and DNA condensing, their transfection efficiency and cytotoxicity were investigated in Neuro2A cells. The polyplexes size were 158.9–264.5 nm and their zeta potentials were 14–30 mV, while their buffering capacity and DNA condensing were not significantly decreased. The highest transfection efficiency in term of C/P ratio was observed in PEI750-10C-68%, PEI750-10C-7%, and PEI750-6C-7% at C/P ratios of 2, 4, and 6, respectively. Altogether, the decanoylcarboxylate-modified PEI with medium grafting percentages showed promising results as gene delivery vector. To sum up, the modification of high molecular weight PEIs by alkylcarboxylate chains is an efficient approach for development of more efficient non-viral vectors.

Genotypic Diversity of Multidrug Resistant Shigella species from Iran

Sajjad Zamanlou,Mohammad Ahangarzadeh Rezaee,Mohammad Aghazadeh,Reza Ghotaslou,Hossein Hosseini Nave,Younes Khalili 대한감염학회 2018 Infection and Chemotherapy Vol.50 No.1

Background: In many developing countries, shigellosis is endemic and also occurs in epidemics and treatment of multidrug-resistant (MDR) isolates are important. The aims of this study were to determine the antimicrobial susceptibility, prevalence of class 1 and 2 integrons and the clonal relatedness of isolates. Materials and Methods: Antimicrobial susceptibility tests were performed by disc diffusion method. Polymerase chain reaction (PCR)-sequencing technique was employed for detection and characterization of integrons. The genetic relatedness was evaluated by using enterobacterial repetitive intergenic consensus (ERIC) PCR. Results: There was a high percentage of resistance to trimethoprim-sulfamethoxazole (TMP/SMX) (93.7%), ampicillin (AMP) (87.3%), streptomycin (STR) (84.5%) and tetracycline (TET) (78.9%). MDR phenotype was seen in 95.1% of total isolates. Most common MDR profile was TMP/SMX/STR/AMP resistant pattern. Among the 142 Shigella spp. analyzed in this study, 28 isolates were positive for class 1 integron with two types of gene cassette arrays (dfrA17/aadA5 = 31.7% and dfrA7 = 3.8%). The class 2 integron was more frequently detected among the isolates (94.7%) with dfrA1/sat1/aadA1 (69.4%) and dfrA1/sat1 (30.6%) gene cassettes. ERIC-PCR results showed 6, 5, 4 and 3 main genotypes among S. flexneri, S. sonnei, S. boydii and S. dysenteriae isolates, respectively. Conclusion: Our findings revealed that multidrug resistant Shigella species with high prevalence of class 2 integron were very common in Iran. In addition, ERIC-PCR patterns showed limited variety of clones are responsible for shigellosis in the region of the study.

Conus Medullaris Teratoma: Case Report and Literature Review

( Ehsan Keykhosravi ),( Amin Tavallaii ),( Hamid Rezaee ),( Kaveh Ebrahimzadeh ),( Masoud Pishjoo ),( Reza Abdi ),( Mona Maftouh ),( Behzad Aminzadeh ) 대한뇌종양학회 대한신경종양학회 2020 Brain Tumor Research and Treatment Vol.8 No.2

Teratomas are benign germ cell tumors that usually found out of their anatomical origin. Teratomas usually are found in sacrococcygeal area, gonads, mediastinum, cervicofacial region and intracranial fossa. Spinal teratomas are rare. In this study we describe a case of conus medullaris teratoma which was diagnosed based on imaging studies. The patient underwent surgery. We did bilateral laminectomy. The mass lesion had an obvious and rigid attachment to the conus medullaris. The wall of the lesion was resected as much as possible, but total resection of the lesion’s wall could not be done due to changes in neural monitoring. Previous related studies are reviewed.

No Detection of Xenotropic Murine Leukemia Virus-Related Viruses in Prostate Cancer in Sanandaj, West of Iran

Khodabandehloo, Mazaher,Hosseini, Weria,Rahmani, Mohammad-Reza,Rezaee, Mohammad-Ali,Hakhamaneshi, Mohammad-Saied,Nikkhoo, Bahram,Jalili, Ali Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.11

Background: Multiple etiologies have been hypothesized for prostate cancer, including genetic defects and infectious agents. A recently reported gamaretrovirus, xenotropic murine leukemia virus-related virus (XMRV) has been reported to be detected in prostate cancer. However, this virus has not been detected in similar groups of patients in other studies. Herein, we sought to detect XMRV in prostate cancers and benign controls in Sanandaj, west of Iran. Materials and Methods: In a case-control study, genomic DNA was extracted from formalin fixed and paraffin embedded prostate tissues from a total of 163 Iranian patients. We developed a conventional and a nested PCR assay using primers targeting to an env specific sequence of XMRV. PCR assays were carried out on 63 prostate cancers and 100 benign prostate hyperplasias. Results: Beta-actin sequences were successfully detected in the DNA extracts from all prostate tissues, confirming DNA extraction integrity. We did not detect XMRV in samples either from prostate cancers or benign prostate hyperplasias using XMRV specific primers. Conclusions: We conclude that in our population XMRV does not play a role in genesis of prostate cancer.

Photocatalytic degradation of organic dyes using WO3-doped ZnO nanoparticles fixed on a glass surface in aqueous solution

Roya Ebrahimi,Afshin Maleki,Yahya Zandsalimi,Reza Ghanbari,Behzad Shahmoradi,Reza Rezaee,Mahdi Safari,주상우,Hiua Daraei,Shivaraju Harikaranahalli Puttaiah,Omid Giahi 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.73 No.-

The present study aimed at evaluating the application of tungsten oxide-doped zinc oxide nanoparticlesfor the photocatalytic degradation of Direct Blue 15 dye in a sequencing batch reactor. ZnO nanoparticleswere doped with WO3 through hydrothermal synthesis method. To characterize the synthesizednanoparticles scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy,atomic force microscopy, zeta potential analysis, and ultraviolet–visible spectroscopy were used. Theradiation source in this study wasfive 6 W UV lamps. Operational parameters affecting the process,namely pH, light intensity, dopant percentage, dye concentration, and contact time, were evaluated. Theresults of the present study revealed that the efficiency of the photocatalytic process for the degradationof organic dyes was higher at acidic pH values than neutral or basic values. In addition, upon increasingthe light intensity from 172 to 505 W/m2, the efficacy of dye degradation was enhanced from 27.8 to73.5%. Increasing the concentration of the dopant percentage from 1 to 5% w/v increased the degradationefficacy from 30.69 to 73.1%. Increasing the initial dye concentration from 20 to 100 mg/L decreased thedegradation efficacy from 86.9 to 37.5%. Photocatalytic process using WO3-doped ZnO nanoparticlesfixedon a glass surface thus was proven to show a good efficiency for the degradation of organic dye in aquaticsolutions.