Geomorphologic Landforms Sorkh Diaj Zanjan

Gholam Hassan Jafari 세계문화관광학회 2011 Conference Proceedings Vol.12 No.-

Geotourist landforms is in fact specifically tourist that had rested from relation process intrusion and extrusion earths forms earth present had resulted of theses. Lovable ions this forms for general humans will have along with diligently that they are tending ground very data of tongue a specialist. Sorkh Dizaj Zanjan is one of the states that there are not accept tourist roundly bat geomorphologic study shows this subject is that local forms will con absorbent more humans on itself providing that humans know data they. This research accomplishes in shape active researcher and use of global mapper software and hydrological formulas doming in local we have attempted that recognition of topic geomorphologic sites of reason they have spatial forms. Pediment studies shows that how many geomorphology cal sites that engender by glacial quaternary or karstique or tectonic process that more they are post climatic inheritance past or neo tectonic.

Optical and Electrical Properties of a Metal-Semiconductor-Metal Material Based on Al-Doped ZnO Films for Use as UV Photodetectors

Sorour Jafari,Mohammad Hassan Yousefi,Fahimeh Zahedi 한국물리학회 2019 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.74 No.11

ZnO and ZnO:Al (aluminum-doped ZnO) thin films were grown on glass substrates at 480$^\circ$C by using a simple flexible spray pyrolysis method. The effects of Al doping on the structural, optical and electrical properties were investigated. X-ray diffraction (XRD) patterns showed successful growth of high-quality polycrystalline films on the substrates. The predominant orientation of the films was the (002) orientation. The microstructural parameters, such as the lattice parameters, the crystallite size ($D$), the microstrain ($\epsilon$), and the dislocation density ($d$) were calculated and found to depend upon the composition. Adding Al to the ZnO crystal structure decreased the crystallite size and increased the residual stress in the thin films. All films were highly transparent in the visible region with an average transmittance of 85 \%. Increasing the amount of the Al dopant increased the optical band gap from 3.26 to 3.34eV. A blue shift of the optical band gap from 400 nm to 380 nm with increasing Al doping percentage was observed in the PL spectrum. The spectrum in the UV range showed 1\% Al emission with a bandwidth of 100 nm (between 350 and 450 nm). Doping improved the electrical conductivity of the ZnO thin films, and the lowest resistivity was found for the thin film with 1\% Al doping. The I-V characteristics of the ZnO:Al thin films were measured in dark and under UV illumination. This study demonstrated that the 1\% Al-doped ZnO thin film exhibited physical properties, allowing better integration in optoelectronic devices.

Cost-Effectiveness Analysis of Breast Cancer Screening in Rural Iran

Zehtab, Nooshin,Jafari, Mohammad,Barooni, Mohsen,Nakhaee, Nouzar,Goudarzi, Reza,Zadeh, Mohammad Hassan Larry Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.2

Background: Although breast cancer is the most common cancer in women, economic evaluation of breast cancer screening is not fully addressed in developing countries. The main objective of the present study was to analyze the cost-effectiveness of breast cancer screening using mammography in 35-69 year old women in an Iranian setting. Materials and Methods: This was an economic evaluation study assessing the cost-effectiveness of a population-based screening program in 35-69 year old women residing in rural areas of South east Iran. The study was conducted from the perspective of policy-makers of insurance. The study population consisted of 35- to 69-year old women in rural areas of Kerman with a population of about 19,651 in 2013. The decision tree modeling and economic evaluation software were used for cost-effectiveness and sensitivity analyses of the interventions. Results: The total cost of the screening program was 7,067.69 US$ and the total effectiveness for screening and no-screening interventions was 0.06171 and 0.00864 disability adjusted life years averted, respectively. The average cost-effectiveness ratio DALY averted US$ for screening intervention was 7,7082.5 US$ per DALY averted and 589,027 US $ for no-screening intervention. The incremental cost-effectiveness ratio DALY averted was 6,264 US$ per DALY averted for screening intervention compared with no-screening intervention. Conclusions: Although the screening intervention is more cost-effective than the alternative (noscreening) strategy, it seems that including breast cancer screening program in health insurance package may not be recommended as long as the target group has a low participation rate.

Wear Behavior of Biodegradable Mg–5Zn–1Y–(0–1)Ca Magnesium Alloy in Simulated Body Fluid

Asma Ghanbari,Hassan Jafari,Faramarz Ashenai Ghasemi 대한금속·재료학회 2020 METALS AND MATERIALS International Vol.26 No.3

In this study, wear behavior of biodegradable Mg–5Zn–1Y–(0–1)Ca alloys is investigated in simulated body fluid. Weartest is performed using a pin-on-disc system, under three different loads of 10, 20 and 40 N, at ambient temperature; andthe whole configuration is exposed to simulated body fluid. The volumetric wear rate and friction coefficient of each alloyare determined. The worn surfaces are analyzed using a scanning electron microscope, equipped with an energy dispersivespectrometer to determine the involved main wear mechanism. The Ca-free alloy contains α-Mg and intermetallic Mg3YZn6,and Ca addition produces another intermetallic Ca2Mg6Zn3. Results show that different wear mechanisms and rates, as wellas friction coefficients, are achieved due to the effect of simulated body fluid on the alloys with regards to the different Cacontent and the presence of corrosion products. Microscopic studies reveal that abrasion is the dominant wear mechanismtaken place in all alloys under all loads. Increasing Ca content leads to wear resistance deterioration while increasing wearload results in decreasing wear rate and friction coefficient of the alloys. The results of the wear rate and friction coefficientof Mg–5Zn–1Y–1Ca alloy exhibit greater instability compared to the other alloys due to its more enhanced corrosion causedby the formation of the intermetallic Ca2Mg6Zn3particles. In total, Ca-free alloy provides the best wear resistance, especiallyat the higher wear load.

Studying the Park-Ang damage index of reinforced concrete structures based on equivalent sinusoidal waves

Moosa Mazloom,Pardis Pourhaji,Masoud Shahveisi,Seyed Hassan Jafari 국제구조공학회 2019 Structural Engineering and Mechanics, An Int'l Jou Vol.72 No.1

In this research, the vulnerability of some reinforced concrete frames with different stories are studied based on the Park-Ang Damage Index. The damages of the frames are investigated under various earthquakes with nonlinear dynamic analysis in IDARC software. By examining the most important characteristics of earthquake parameters, the damage index and vulnerability of these frames are investigated in this software. The intensity of Erias, velocity spectral intensity (VSI) and peak ground velocity (PGV) had the highest correlation, and root mean square of displacement (Drms) had the lowest correlation coefficient among the parameters. Then, the particle swarm optimization (PSO) algorithm was used, and the sinusoidal waves were equivalent to the used earthquakes according to the most influential parameters above. The damage index equivalent to these waves is estimated using nonlinear dynamics analysis. The comparison between the damages caused by earthquakes and equivalent sinusoidal waves is done too. The generations of sinusoidal waves equivalent to different earthquakes are generalized in some reinforced concrete frames. The equivalent sinusoidal wave method was exact enough because the greatest difference between the results of the main and artificial accelerator damage index was about 5 percent. Also sinusoidal waves were more consistent with the damage indices of the structures compared to the earthquake parameters.

Thermorheological Complexity of a Dynamically Asymmetric Miscible Blend: The Improving Role of Na+-MMT Nanoclay

Mahdi Ghelichi,Nader Taheri Qazvini,Seyed Hassan Jafari,Hossein Ali Khonakdar 한국고분자학회 2013 Macromolecular Research Vol.21 No.4

The influence for the minor amount of sodium montmorillonite (Na+-MMT) nanoclay on the thermorheological complexity of a miscible blend of 20 wt% poly(ethylene oxide) (PEO) in poly(methyl methacrylate)(PMMA) is studied. The dispersion of Na+-MMT in the PEO/PMMA is assessed via X-ray diffraction. The empirical principle of time-temperature superposition is found to be partially restored in the case of blend nanocomposite,whereas it fails for the neat PEO/PMMA blend. The relaxation times of each component are determined from the oscillatory shear rheometry data in the form of a monomeric friction coefficient. The chain dynamics of components is coupled in the presence of hydrophilic nanoclay, which preferentially adsorbs PEO. The self-concentration model of Lodge and McLeish successfully describes the temperature dependence of the PMMA monomeric friction coefficient in both the neat and blend nanocomposite in regards to the temperature range studied.

Preparation and Release Properties of Electrospun Poly(vinyl alcohol)/ Poly(ε-caprolactone) Hybrid Nanofibers: Optimization of Process Parameters via D-Optimal Design Method

Payam Zahedi,Iraj Rezaeian,Seyed Hassan Jafari,Zeinab Karami 한국고분자학회 2013 Macromolecular Research Vol.21 No.6

The main purpose of this work was to develop biomedical electrospun nanofibrous mats based on a poly(vinyl alcohol)/poly(ε-caprolactone) (80/20) hybrid with a defined drug release rate using tetracycline hydrochloride as a model drug. The electrospinning process parameters, such as polymer solution concentration, distance between injecting syringe tip/collector, voltage, injected flow rate and the polyvinyl alcohol crosslinking time were optimized via a D-optimal design method for a suitable nanofiber diameter with an optimal drug release rate. The morphology of nanofibers and their mean diameters were studied by a scanning electron microscopy technique. The results showed that the mean diameters of nanofibers were significantly reduced after drug loading. The swelling,weight loss and biodegradability of nanofibers samples investigated by FTIR were also determined. Two main mechanisms via penetration and erosion were evaluated. In vitro drug release in a phosphate buffer environment at pH=7.2for the samples demonstrated that the polymer type and hydrophilic nature of the polymer/drug system is very effective in the kinetics and mechanism of drug release. Hybridization of poly(vinyl alcohol)/poly(ε-caprolactone) with a known ratio showed to be a suitable and useful method in the electrospinning of nanofibers samples for superior control of the drug release rate. Finally, nanofibrous mats of polyvinyl alcohol and polyvinyl alcohol/poly(ε-caprolactone)hybrid (80/20) had much better drug release rate characteristics for tetracycline hydrochloride as a model drug compared with cast film samples loaded with the same drug.

Simulation and in vitro evaluations of microfluidically-fabricated clarithromycin-poly (e-caprolactone) nanoparticles

Beeta Tavana,Alireza Khatibi,Saeed Jafarkhani,Payam Zahedi,Mohammad Hossein Zamani,Seyed Hassan Jafari,Mohammad Najafi 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.124 No.-

Clarithromycin (CLR)-loaded poly (e-caprolactone) (PCL) nanoparticles (NPs) were synthesized usingmicrofluidics (MF) with square-shaped (MF1), and three-channel (MF2), geometries as well as conventionalbulk mixing (BM). Based on Comsol simulation results of MF chips, the flow rate ratio, nonsolventphase flow rate, and polymer solution concentration were optimized 0.05, 50 mL h1, and 0.2(%w/v), respectively; thereby, representing MF1 geometry with highest homogenous mixing. Characterization studies indicated that MF1-based NPs possessed smaller average diameter (91 nm),narrower polydispersity index (0.13) and higher zeta potential (-44 mV) compared to those NPs synthesizedby MF2 and BM methods. Moreover, MF1-aided synthesis of NPs exhibited the encapsulation efficiencyof approximately 81% and loading capacity of around 13%. Investigating CLR release behavior atdifferent pHs also demonstrated that the MF1-based NPs experienced the most controlled release, followedthe Fickian diffusion mechanism. The controlled release of MF1-based NPs was confirmed by evaluatingtheir inhibitory effect against specific cytokines on BEAS-2B as bronchitis cell line via a series ofin vitro experiments including real time-polymerase chain reaction and flow cytometry. Eventually, theantibacterial properties of the samples were studied on two prevalent bacterial strains and the obtainedobservations revealed that MF1-based NPs encompassed the best performance in controlled release ofCLR with respect to the other samples.