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Adsorption of Nile Blue A from aqueous solution by different nanostructured carbon adsorbents
Shahryar Abbasi,Hadi Noorizadeh 한국탄소학회 2017 Carbon Letters Vol.23 No.-
Dyes are widely used in various industries including textile, cosmetic, paper, plastics, rubber, and coating, and their discharge into waterways causes serious environmental and health problems. Four different carbon nanostructures, graphene oxide, oxidized multi-walled carbon nanotubes, activated carbon and multi-walled carbon nanotubes, were used as adsorbents for the removal of Nile Blue A (NBA) dye from aqueous solution. The four carbon nanostructures were characterized by scanning electron microscope and X-ray diffractometer. The effects of various parameters were investigated. Kinetic adsorption data were analyzed using the first-order model and the pseudo-second-order model. The regression results showed that the adsorption kinetics were more accurately represented by the pseudo-second-order model. The equilibrium data for the aqueous solutions were fitted to Langmuir and Freundlich isotherms, and the equilibrium adsorption of NBA was best described by the Langmuir isotherm model. This is the first research on the removal of dye using four carbon nanostructures adsorbents.
Design and fabrication of a new piezoelectric paper feeder actuator without mechanical parts
Shahryar Ghorbanirezaei,Yousef Hojjat,Mojtaba Ghodsi 국제구조공학회 2019 Smart Structures and Systems, An International Jou Vol.24 No.2
A piezoelectric paper feeder actuator using Micro Virtual Roller (MVR) is proposed, designed, fabricated and tested. This actuator can drive a sheet of paper forward or backward without any mechanical parts, such as the costly and heavy rollers used in traditional paper feeders. In this paper feeder actuator, two vibrating stators which produce traveling waves are used to drive the paper. The vibrations of the stators are similar to those of piezoelectric motors and follow a similar procedure to move the paper. A feasibility study simulated the actuator in COMSOL Multiphysics Software. Traveling wave and elliptical trajectories were obtained and the dimensions of the stator were optimized using FEM so that the paper could move at top speed. Next, the eigenfrequencies of the actuator was determined. Experimental testing was done in order to validate the FEM results that revealed the relationships between speed and parameters such as frequency and voltage. Advantages of this new mechanism are the sharp decrease in power consumption and low maintenance.
A comparative study of the Gini coefficient estimators based on the regression approach
Mirzaei, Shahryar,Borzadaran, Gholam Reza Mohtashami,Amini, Mohammad,Jabbari, Hadi The Korean Statistical Society 2017 Communications for statistical applications and me Vol.24 No.4
Resampling approaches were the first techniques employed to compute a variance for the Gini coefficient; however, many authors have shown that an analysis of the Gini coefficient and its corresponding variance can be obtained from a regression model. Despite the simplicity of the regression approach method to compute a standard error for the Gini coefficient, the use of the proposed regression model has been challenging in economics. Therefore in this paper, we focus on a comparative study among the regression approach and resampling techniques. The regression method is shown to overestimate the standard error of the Gini index. The simulations show that the Gini estimator based on the modified regression model is also consistent and asymptotically normal with less divergence from normal distribution than other resampling techniques.
Yahyapour, Yousef,Shamsi-Shahrabadi, Mahmoud,Mahmoudi, Mahmoud,Siadati, Sepideh,Shahryar, Shefaei Shahryar,Shokri-Shirvani, Javad,Mollaei, Hamid,Monavari, Seyed Hamid Reza Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.4
Introduction: HPV has been found repeatedly in esophageal squamous cell carcinoma (ESCC) tissues. However, reported detection rates of HPV DNA in these tumors have varied markedly. Differences in detection methods, sample types, and geographic regions of sample origin have been suggested as potential causes of variation. We have reported that infection of HPV DNA in ESCC tumors depends on anatomical sites of esophagus of the patients from Mazandaran, north of Iran. Materials and Methods: HPV DNA was examined in 46 upper, 69 middle and 62 lower third anatomical sites of esophageal squamous cell carcinoma specimens collected from Mazandaran province in north Iran, near the Caspian Littoral as a region with high incidence of ESCC. HPV L1 DNA was detected using Qualitative Real time PCR and MY09/MY11 primers. Results: 28.3% of upper, 29% of middle and 25.8% of lower third of ESCC samples were positive for HPV DNA. 13.6% for males and 14.1% for females were HPV positive in all samples. Conclusions: HPV infection is about one third of ESCC in this area. Findings in this study increase the possibility that HPV is involved in esophageal carcinogenesis. Further investigation with a larger sample size is necessary.
Sajad Fakhri,Shahryar Sabouri,Amir Kiani,Mohammad Hosein Farzaei,Khodabakhsh Rashidi,Ahmad Mohammadi-Farani,Ehsan Mohammadi-Noori,Fatemeh Abbaszadeh 대한통증학회 2022 The Korean Journal of Pain Vol.35 No.3
Background: Spinal cord injury (SCI) is one of the most debilitating disorders throughout the world, causing persistent sensory-motor dysfunction, with no effective treatment. Oxidative stress and inflammatory responses play key roles in the secondary phase of SCI. Naringenin (NAR) is a natural flavonoid with known antiinflammatory and antioxidative properties. This study aims at evaluating the effects of intrathecal NAR administration on sensory-motor disability after SCI. Methods: Animals underwent a severe compression injury using an aneurysm clip. About 30 minutes after surgery, NAR was injected intrathecally at the doses of 5, 10, and 15 mM in 20 μL volumes. For the assessment of neuropathic pain and locomotor function, acetone drop, hot plate, inclined plane, and Basso, Beattie, Bresnahan tests were carried out weekly till day 28 post-SCI. Effects of NAR on matrix metalloproteinase (MMP)-2 and MMP-9 activity was appraised by gelatin zymography. Also, histopathological analyses and serum levels of glutathione (GSH), catalase and nitrite were measured in different groups. Results: NAR reduced neuropathic pain, improved locomotor function, and also attenuated SCI-induced weight loss weekly till day 28 post-SCI. Zymography analysis showed that NAR suppressed MMP-9 activity, whereas it increased that of MMP-2, indicating its anti-neuroinflammatory effects. Also, intrathecal NAR modified oxidative stress related markers GSH, catalase, and nitrite levels. Besides, the neuroprotective effect of NAR was corroborated through increased survival of sensory and motor neurons after SCI. Conclusions: These results suggest intrathecal NAR as a promising candidate for medical therapeutics for SCI-induced sensory and motor dysfunction.
Study on magnetorheological damper stiffness shift
Mohammad H. Jafarkarimi,Shahryar Ghorbanirezaei,Yousef Hojjat,Vahid Sabermand 국제구조공학회 2020 Smart Structures and Systems, An International Jou Vol.25 No.3
Electrical current is usually used to change the damping force of Magnetorheological Dampers (MRDs). However, changing the electrical current could shift the stiffness of the system, the phenomenon that was not considered carefully. This study aims to evaluate this shift. A typical MRD was designed, optimized, and fabricated to do some accurate and detailed experimental tests to examine the stiffness variation. The damper is equipped with a circulating system to prevent the deposition of particles when it is at rest. Besides that, a vibration setup was developed for the experimental study. It is capable of generating vibration with either constant frequency or frequency sweep and measure the amplitude of vibration. The damper was tested by the vibrating setup, and it was concluded that with a change in electrical current from 0 to 1.4 A, resonant frequency would change from 13.8 Hz to 16 Hz. Considering the unchanging mass of 85.1 kg, the change in resonant frequency translates as a shift in stiffness, which changes from 640 kN/m to 860 kN/m.
Predictors of Colorectal Cancer Survival in Golestan, Iran: A Population-based Study
Mohammad Aryaie,Gholamreza Roshandel,Shahryar Semnani,Mohsen Asadi-Lari,Mohsen Aarabi,Mohammad Ali Vakili,Vahideh Kazemnejhad,Seyed Mehdi Sedaghat,Masoud Solaymani-Dodaran 한국역학회 2013 Epidemiology and Health Vol.35 No.-
OBJECTIVES: We aimed to investigate factors associated with colorectal cancer survival in Golestan, Iran. METHODS: We used a population based cancer registry to recruit study subjects. All patients registered since 2004 were contacted and data were collected using structured questionnaires and trained interviewers. All the existing evidences to determine the stage of the cancer were also collected. The time from first diagnosis to death was compared in patients according to their stage of cancer using the Kaplan-Meir method. A Cox proportional hazard model was built to examine their survival experience by taking into account other covariates. RESULTS: Out of a total of 345 subjects, 227 were traced. Median age of the subjects was 54 and more than 42% were under 50 years old. We found 132 deaths among these patients, 5 of which were non-colorectal related deaths. The median survival time for the entire cohort was 3.56 years. A borderline significant difference in survival experience was detected for ethnicity (log rank test, p=0.053). Using Cox proportional hazard modeling, only cancer stage remained significantly associated with time of death in the final model. CONCLUSIONS: Colorectal cancer occurs at a younger age among people living in Golestan province. A very young age at presentation and what appears to be a high proportion of patients presenting with late stage in this area suggest this population might benefit substantially from early diagnoses by introducing age adapted screening programs.
Mohammdad Hadi Nematollahi,Shahryar Babaei,Reza Abedini 한국화학공학회 2019 Korean Journal of Chemical Engineering Vol.36 No.5
Owing to the potential of polymeric and nanocomposite membranes for industrial application in CO2 capturing and gas separation processes, permeation properties of CO2, N2 and O2 through the polymer matrix have been an object of extensive research. We measured the permeation rates of gases (pure and mixed gas) within a novel nanocomposite membrane composed of poly tetramethyleneglycol (PTMG), hexamethylene diisocyanate (HDI), and diamine chain extender, 4,4- methylenebis(2-chloroaniline) (MOCA) at various silica loadings and operating conditions. The novel polyurethane was prepared by a two-step bulk polymerization technique based on the molar ratios of the used constituents 1 : 3 : 2 for PTMG: HDI :MOCA, respectively. The FTIR spectra indicated that the extent of phase separation decreased by increase in the SiO2 content. From the DSC and XRD analyses, the existence of small crystalline areas within the soft and hard segments of matrix was proved. High thermal stability of new nanocomposites was authenticated by a 90 oC increase in the decomposition temperature upon including the SiO2 particles into the polymer matrix. By providing a longer diffusion path, a reduction in the permeation of penetrants occurred after the incorporation of SiO2 content. By raising the temperature from 25 to 45 oC, the gas permeation value of CO2, O2 and N2 rose steeply: 35, 54 and 81% in neat PU and 49, 64 and 137% in PU containing 15 wt%, respectively. Conversely, the obtained results for increasing the feed gas pressure from 6 to 10 bar revealed that the penetration of non-condensable gases, O2 and N2, decreased while the permeation rate of CO2 polar gas surged dramatically. Nevertheless, a simultaneous increment in the selectivity amounts of both gas pairs was revealed. For the gaseous mixtures, the trend of changes in permeability and selectivity values were almost identical with those of pure gas: decrease in permeation, and vice versa increase in gas pair selectivity. Eventually, the separation results of the prepared membranes indicated a strong tendency to move towards Robeson’s line by incorporation of SiO2 nanoparticles into the matrix of membranes.