Conservation of Iranian Olive Genetic Resources

Mehdi Hosseini-Mazinani,Saeedeh Ataei,Zahra Nourmohammadi,Ali Asghar Zeinanloo 한국원예학회 2006 한국원예학회 기타간행물 Vol.- No.-

Cyclic Performance and Mechanical Characteristics of the Oval-Shaped Damper

Mehdi Najari Varzaneh,Mahmood Hosseini 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.11

Every year earthquake damage causes hundreds of death all over the world. As much as possible, buildings should be kept in the elastic zone during an earthquake, therefore, the failure of building the main member is reduced. This paper investigated an oval steel shaped yielding damper used for seismic protection of chevron steel braced frames. The damper is designed to deform in-elastically under shear deformation to become energy dissipated. This oval steel shaped damper improves the braces buckling problem and reduces the required area cross section of chevron steel bracing members. To do this, eight models of the damper are proposed. For this purpose, finite element (FE) analysis with ABAQUS software is used to investigate and model the oval-shaped damper (OSD). The present study also investigated the damper strength parameters and seismic performance for applying to the steel braces frame. It is shown that the damper added between the chevron braces and the upper beam can reduce the lateral displacement and base frame force. Hence, the oval steel shaped damper is capable to absorb a great amount of energy with a stable hysteresis behavior. To do this, relationships are proposed and developed based on the maximum capability of the damper. The results show that this damper is responsible for absorbing input energy and increasing ductility frame coefficient. By comparing the analytical method and theoretical results, it is calculated that the proposed equations can be adapted to calculate seismic parameters like ultimate stress, ultimate shear force, plastic moment, elastic stiffness, stiffness degradation, deformation capacity, and resistance of the damper and calculate the exact location of plastic hinge. The structural designer, researchers and someone who like to develop the researches, it can be used and benefit for structural engineering.

Seasonal monitoring of urban heat island using multi-temporal Landsat and MODIS images in Tehran

Mehdi Bokaie,Aliakbar Shamsipour,Padideh Khatibi,Ali Hosseini 서울시립대학교 도시과학연구원 2019 도시과학국제저널 Vol.23 No.2

This study aimed to investigate the relationship between seasonal changes in land surface temperature (LST) and various land use/land cover (LULC) classes in Tehran in 2010. For this purpose, urban heat island (UHI) cores were detected. The relationship between spatiotemporal variations of UHIs and the LULC classes was studied. The results showed that UHIs have different causes due to the type of LULC classes in the region. The average temperature of the five LULC classes in different seasons revealed full compliance of the spreading pattern of UHIs in the city with the type of LULC. Daytime and nighttime MODIS LST maps were prepared to verify the results. The daytime LST map also confirmed the compliance of the spatial pattern of UHIs with the types of LULC. The consequences from the nighttime LST map revealed the movement and conduction of main cores of heat islands towards the central and densely populated areas of the city, which could be expected to be due to the high absorption rate of heat during the day by unnatural materials and energy emissions at night.

Simplified approach on modeling of embedded reinforcements in flexural concrete members

Hosseini, Seyed Muoud,Ghomian, Majid,BaniAsad, Elham,Dehestani, Mehdi Techno-Press 2021 Advances in concrete construction Vol.12 No.3

Several factors need to be considered in modeling of reinforced concrete beams. Bond-slip is one of the most important factors that play a key role in the behavior of reinforced concrete structures, under static and dynamic loads. A comparison between the results of experimental tests and numerical models show that considering a complete bond (perfect with no slip) instead of real bond-slip phenomenon, in numerical finite element models leads to higher estimations for the stiffness. In this study, the effects of the bond-slip phenomenon on the behavior of the reinforced concrete beams are considered. It is shown that the influence of bond-slip behavior between steel and concrete depends on the compressive strength of concrete, the concrete cover, stirrups and rebar diameter. Subsequently, a method is proposed to consider the effects of the interfacial behavior between concrete and rebar while a complete bond assumption remains and the rebar is introduced as embedded element in concrete. The bond-slip effect is considered by adding an equivalent strain of bond to the strain of steel rebar and then modifying the terms of the modulus of elasticity of steel. Validation model and parametric analyses are conducted to consider the effects of bond-slip properties and other parameters affecting the behavior of reinforced concrete beams.

Effectiveness of the back school program on the low back pain and functional disability of Iranian nurse

Mehdi Pakbaz,Mohammad Ali Hosseini,Seyedeh Zahra Aemmi,Sepideh Gholami 한국운동재활학회 2019 JER Vol.15 No.1

Human Error Analysis in a Permit to Work System: A Case Study in a Chemical Plant

Mehdi Jahangiri,Naser Hoboubi,Akbar Rostamabadi,Sareh Keshavarzi,Ali Akbar Hosseini 한국산업안전보건공단 산업안전보건연구원 2016 Safety and health at work Vol.7 No.1

Background: A permit to work (PTW) is a formal written system to control certain types of work which are identified as potentially hazardous. However, human error in PTW processes can lead to an accident. Methods: This cross-sectional, descriptive study was conducted to estimate the probability of human errors in PTWprocesses in a chemical plant in Iran. In the first stage, through interviewing the personnel and studying the procedure in the plant, the PTW process was analyzed using the hierarchical task analysis technique. In doing so, PTWwas considered as a goal and detailed tasks to achieve the goal were analyzed. In the next step, the standardized plant analysis risk-human (SPAR-H) reliability analysis method was applied for estimation of human error probability. Results: The mean probability of human error in the PTW system was estimated to be 0.11. The highest probability of human error in the PTW process was related to flammable gas testing (50.7%). Conclusion: The SPAR-H method applied in this study could analyze and quantify the potential human errors and extract the required measures for reducing the error probabilities in PTW system. Some suggestions to reduce the likelihood of errors, especially in the field of modifying the performance shaping factors and dependencies among tasks are provided.

Human Error Analysis in a Permit to Work System: A Case Study in a Chemical Plant

Jahangiri, Mehdi,Hoboubi, Naser,Rostamabadi, Akbar,Keshavarzi, Sareh,Hosseini, Ali Akbar Occupational Safety and Health Research Institute 2016 Safety and health at work Vol.7 No.1

Background: A permit to work (PTW) is a formal written system to control certain types of work which are identified as potentially hazardous. However, human error in PTW processes can lead to an accident. Methods: This cross-sectional, descriptive study was conducted to estimate the probability of human errors in PTWprocesses in a chemical plant in Iran. In the first stage, through interviewing the personnel and studying the procedure in the plant, the PTW process was analyzed using the hierarchical task analysis technique. In doing so, PTWwas considered as a goal and detailed tasks to achieve the goal were analyzed. In the next step, the standardized plant analysis risk-human (SPAR-H) reliability analysis method was applied for estimation of human error probability. Results: The mean probability of human error in the PTW system was estimated to be 0.11. The highest probability of human error in the PTW process was related to flammable gas testing (50.7%). Conclusion: The SPAR-H method applied in this study could analyze and quantify the potential human errors and extract the required measures for reducing the error probabilities in PTW system. Some suggestions to reduce the likelihood of errors, especially in the field of modifying the performance shaping factors and dependencies among tasks are provided.

On the Evaluation of the Use of EKBs to Improve Seismic Performance of Steel Frames

Behrokh Hosseini Hashemi,Mehdi Alirezaei 한국강구조학회 2018 International Journal of Steel Structures Vol.18 No.1

In this paper a new eccentric and knee bracing system named Eccentrically Knee Brace (EKB) is introduced and its merits to increase seismic performance of the steel frames is investigated. To assess the seismic behavior of this system compared to other steel braced systems, numerical modeling using finite element software is implemented. Subjected to moderate earthquakes, the knee element exclusively dissipates the seismic energy through plastic shear distortion, while the other structural elements remain in elastic range. Under severe earthquakes, plastic deformation of the knee element will be halted by the stopper subsequently causing yielding of the link element. Finally, a simplified analytical model is derived to predict the bilinear behavior of the EKBs.

Modeling of P-ρ-T properties of ionic liquids using ISM equation of state: Application to pure component and binary mixtures

Mohammad Mehdi Papari,Sayed Mostafa Hosseini,Fatemeh Fadaei-Nobandegani,Jalil Moghadasi 한국화학공학회 2012 Korean Journal of Chemical Engineering Vol.29 No.11

Ihm-Song-Mason (ISM) equation of state (EOS) has been previously employed for modeling the volumetric properties of ionic liquids (ILs). The novelty of the present work is in replacing the macroscopic scaling constants with microscopic ones. Three temperature-dependent parameters that appeared in the EOS, which are universal functions of the reduced temperature, were determined using these new microscopic scaling constants. These parameters are the effective hard-sphere diameter (σ) and the non-bonded interaction energy between two spheres (ε). The present EOS is evaluated by examination of 3997 experimental density data points for five classes of ILs. The average absolute deviation (AAD) of the calculated densities from literature values was found to be of the order of 0.38%. Our calculations involved a broad range of temperature from 293 K to 472 K and pressures from 0.1MPa up to 200MPa. Another aspect of the present study is the extension of the proposed EOS to predict density of binary mixtures involving IL+ water and IL+ IL. In the case of binary mixtures, 898 data points were taken to assess the capability of the EOS. The overall AAD of the calculated mixture densities from the literature ones was within 0.43%.

Assessing the spatial distribution of sports spaces within walking distance in Tehran

Salarvandian Fatemeh,Hosseini Seyed Ali,Moradi Aram,Karoubi Mehdi 서울시립대학교 도시과학연구원 2020 도시과학국제저널 Vol.24 No.4

Spatial equity in urban sports services has received a lot of attention due to the importance of physical activities in public health-related issues. Using GIS network and spatial statistical analysis, a total number of 22 regions in Tehran were studied to investigate the possible differences in terms of physical activity spaces per capita and pedestrian accessibility to sports facilities services. The findings revealed that some regions have an undersupply of sports spaces, while others have insufficient access to these services. Considering the population density, the results showed that the regions with the highest population and residential density have fewest facilities. Unexpectedly, regions with more sports spaces per capita appeared to have the lowest accessibility to the sports facilities. It was also found that having more sports spaces available per capita does not necessarily imply greater accessibility within walking distances. This means major sports facilities are located in areas with relatively minimal opportunities to use them.