Original Article : Effects of Salinity Changes on Hematological Responses in Juvenile Ship Sturgeon Acipenser nudiventris

( Erfan Shahkar ),( Dae Jung Kim ),( Mahmoud Mohseni ),( Hyeon Ho Yun ),( Sung Chul C Bai ) 한국수산과학회(구 한국수산학회) 2015 Fisheries and Aquatic Sciences Vol.18 No.1

A 10-day trial was conducted to evaluate the salinity tolerance and hematological responses of juvenile ship sturgeon Acipenser nudiventris under different salinity levels. A total of 240 fish averaging 6.2 ± 0.13 g (mean ± SD) were randomly distributed into 12 tanks in groups of 20, and each tank was then randomly assigned to one of three replicates of four different salinities at 0, 4, 8 and 12‰. At the end of 10 days of experimental period, plasma protein value of fish exposed to 0‰ and 4‰ salinities was significantly higher than those of fish exposed to 8‰ and 12‰ salinities (P < 0.05). Significantly higher values for plasma cortisol and glucose were obtained in fish exposed to 12‰ salinity compared to the fish exposed to 0‰ and 4‰ salinities (P < 0.05). Plasma potassium and sodium values increased significantly by increment of salinity levels (P < 0.05). Therefore, these results indicated that in natural environments, juvenile ship sturgeon, A. nudiventris in migratory populations could be able to migrate and adjust successfully into brackish water with a salinity of up to 8‰ without any short-term hematological stress responses.

Effect of maternal smoking during pregnancy on Tourette syndrome and chronic tic disorders among offspring: a systematic review and meta-analysis

( Erfan Ayubi ),( Kamyar Mansori ),( Amin Doosti-Irani ) 대한산부인과학회 2021 Obstetrics & Gynecology Science Vol.64 No.1

Current studies have controversial reports about the effect of maternal smoking during pregnancy (MSDP) on the risk of psychiatric disorders among offspring. The purpose of this systematic review and meta-analysis was to assess the effect of MSDP on the risk of Tourette syndrome (TS) and chronic tic disorders (CTD) among offspring. A systematic search using PubMed, Scopus, and Web of Science was conducted up to July 2019 to retrieve potential studies in English. Fixed and random-effects meta-analyses was performed to estimate pooled relative risk (RR) with 95% confidence interval (CI) according to heterogeneity. The methodological quality of the included studies was evaluated using the Newcastle-Ottawa Scale. Heterogeneity among studies was explored using the I² statistic. Of the 641 studies from the initial search, 7 were included in the quantitative synthesis (3 cohort and 4 case control studies). Overall, MSDP increased the risk of TS and CTD among the offspring by 35% (pooled RR, 1.35; 95% CI, 1.17-1.56; I²=45.8%; P-value=0.08). The results of this meta-analysis revealed that there is a significant association between MSDP and the risk of TS and CTD in offspring, and MSDP may be considered a potential risk factor for TS and CTD.

Prediction of TiN Coating Adhesion Strength on Aerospace AL7075-T6 Alloy Using Fuzzy Rule Based System

Erfan Zalnezhad,Ahmed Aly Diaa Mohammed Sarhan,Mohd Hamdi 한국정밀공학회 2012 International Journal of Precision Engineering and Vol. No.

In this research work, predicting of titanium nitride (TiN) coating adhesion on AL7075-T6 is presented. First TiN was coated on Al7075-T6 in different conditions and the surfaces adhesion of TiN coated specimens were measured using micro scratch force machine. Second a fuzzy logic model was established to predict the of TiN coating adhesion on AL7075-T6with respect to changes in input process parameters, DC power, DC bias voltage, and nitrogen flow rate based on the tried data obtained from the scratch force test. Four membership functions are allocated to be connected with each input of the model. Third, new five experimental tests were carried out to verify the predicted results achieved via fuzzy logic model. The result indicated settlement between the fuzzy model and experimental results with the 95.534% accuracy.

Surface Hardness Prediction of CrN Thin Film Coating on AL7075-T6 Alloy Using Fuzzy Logic System

Erfan Zalnezhad,Ahmed Aly Diaa Mohammed Sarhan,Mohd Hamdi 한국정밀공학회 2013 International Journal of Precision Engineering and Vol. No.

In recent years, CrN coating has been identified as one of the most promising protective layers on surfaces of tools and dies due to its excellent mechanical properties, corrosion resistance, and surface hardness. This study presents the predicting of chromium nitride (CrN) coating surface hardness on AL7075-T6 using fuzzy logic technique. First, Al7075-T6 was coated with CrN at different parameter conditions, after which the surfaces hardness of the CrN-coated specimens was measured using a micro hardness machine. Next, a fuzzy logic model was established to predict the surface hardness of CrN coating on AL7075-T6 with respect to changes in input process parameters, DC power, temperature, and nitrogen flow rate based on the trained data obtained from the micro hardness test. Three membership functions were allocated in connection with each model input. Finally, five new experimental tests were carried out to verify the predicted results achieved via the fuzzy logic model. The results indicate an agreement between the fuzzy model and experimental results with 94.664% accuracy.

Efficiency Analysis of Shot Peening Parameters on Variations of Hardness, Grain Size and Residual Stress via Taguchi Approach

Erfan Maleki,Okan Unal,Kazem Reza Kashyzadeh 대한금속·재료학회 2019 METALS AND MATERIALS International Vol.25 No.6

In the present study, the main purpose is to detect the most key factors of shot peening (SP) process on the microhardness,grain size, and residual stress of AISI 1060 high carbon steel. The specimens were treated using various types of SP processnamely conventional shot peening and severe shot peening. Several experiments were performed to study metallurgical andmechanical properties of AISI 1060 steel. Almen intensity and surface coverage from one side and microhardness, grainsize, and residual stress from the other side were considered as input and output parameters for the design of experimentmethodology, respectively. The L18(21 and 31) mixed level of Taguchi orthogonal array design was used to study all cases. The test results were investigated by signal-to-noise ratio formula. It was identified that the surface coverage is the most keyfactors for shot peening process considering the affected depth. Also, the effect of this parameter on the microhardness, grainsize and residual stress was obtained approximately 68, 89 and 57%, respectively. Eventually, the results obtained from allTaguchi sensitivity analysis indicated that it would be better to adjust the surface coverage factor in comparison with Almenintensity factor in order to create the surface compressive residual stress on the material and consequently to increase thefatigue lifetime of component using shot peening treatment.

Spatial modeling of cutaneous leishmaniasis in Iranian army units during 2014-2017 using a hierarchical Bayesian method and the spatial scan statistic

Erfan Ayubi,Mohammad Barati,Arasb Dabbagh Moghaddam,Ali Reza Khoshdel 한국역학회 2018 Epidemiology and Health Vol.40 No.-

OBJECTIVES: This study aimed to map the incidence of cutaneous leishmaniasis (CL) in Iranian army units (IAUs) and to identify possible spatial clusters. METHODS: This ecological study investigated incident cases of CL between 2014 and 2017. CL data were extracted from the CL registry maintained by the deputy of health of AJA University of Medical Sciences. The standardized incidence ratio (SIR) of CL was computed with a Besag, York, and Mollié model. The purely spatial scan statistic was employed to detect the most likely high- and low-rate clusters and to obtain the observed-to-expected (O/E) ratio for each detected cluster. The statistical significance of the clusters was assessed using the log likelihood ratio (LLR) test and Monte Carlo hypothesis testing. RESULTS: A total of 1,144 new CL cases occurred in IAUs from 2014 to 2017, with an incidence rate of 260 per 100,000. Isfahan and Khuzestan Provinces were found to have more CL cases than expected in all studied years (SIR>1), while Kermanshah, Kerman, and Fars Provinces were observed to have been high-risk areas in only some years of the study period. The most significant CL cluster was in Kermanshah Province (O/E, 67.88; LLR, 1,200.62; p<0.001), followed by clusters in Isfahan Province (O/E, 6.02; LLR, 513.24; p<0.001) and Khuzestan Province (O/E, 2.35; LLR, 73.71; p<0.001), while low-rate clusters were located in the northeast areas, including Razavi Khorasan, North Khorasan, Semnan, and Golestan Provinces (O/E, 0.03; LLR, 95.11; p<0.001). CONCLUSIONS: This study identified high-risk areas for CL. These findings have public health implications and should be considered when planning control interventions among IAUs.

NEW OPTIMAL POWER MANAGEMENT STRATEGY FOR SERIES PLUG-IN HYBRID ELECTRIC VEHICLES

Erfan Taherzadeh,Shahram Javadi,Morteza Dabbaghjamanesh 한국자동차공학회 2018 International journal of automotive technology Vol.19 No.6

Recently Plug-in hybrid electric vehicles (PHEVs) have gained increasing attention due to their ability to reduce the fuel consumption and emissions. In this paper a new efficient power management strategy is proposed for a series PHEV. According to the battery state of charge (SOC) and vehicle power requirement, a new rule-based optimal power controller with four different operating modes is designed to improve the fuel economy of the vehicle. Furthermore, the teaching-learning based optimization (TLBO) method is employed to find the optimal engine power and battery power under the specified driving cycle while the fuel consumption is considered as the fitness function. In order to demonstrate the effectiveness of the proposed method, four different driving cycles with various numbers of driving distances for each driving cycle are selected for the simulation study. The performance of the proposed optimal power management strategy is compared with the rule-based power management method. The results verify that the proposed power management method could significantly improve the fuel economy of the series PHEV for different driving conditions.

Effect of Base Flow and Rainfall Excess Separation on Runoff Hydrograph Estimation using Gamma Model (Case Study: Jong Catchment)

Erfan Bahrami,Omolbani Mohammadrezapour,Meysam Salarijazi,Parviz Haghighat Jou 대한토목학회 2019 KSCE JOURNAL OF CIVIL ENGINEERING Vol.23 No.3

A forecast of runoff hydrograph leads to effective decision making in flood management. In this study, effect of three base flow separation methods- straight line (DRH1), fixed base (DRH2), and variable slope (DRH3) and two methods of excess rainfall estimation (Ø index and SCS (Soil Conservation Service) method) with six different rainfall- runoff events are studied on the flood hydrograph simulation. The 6 rainfall-runoff events recorded at Jong catchment in Iran were used for this study. The Percentage Error in Volume (PEV), Percentage Error in Peak (PEP), Percentage Error in Time to Peak (PETP), Nash–Sutcliffe Coefficient (NSC), R2 and Root Mean Square Error (RMSE), were also used to evaluate the results. The results show that the combination of SCS-DRH2 method is the best combination of base flow separation - excess rainfall for improving the accuracy of the model in predicting the hydrograph shape. Also, in estimating the flood volume, the SCS-DRH3 and SCS-DRH1 are the best combination in estimating peak flood and time to peak the flood respectively. The analysis of the results suggests that the combination of SCS-DRH2 is the best combination in improving the accuracy of Gamma model.

Plasticity Constitutive Modeling of Partially Confined Concrete with Steel Jacketing

Erfan Shafei,Javad Mokari Rahmdel 대한토목학회 2017 KSCE JOURNAL OF CIVIL ENGINEERING Vol.21 No.7

Current research offers experimental and numerical investigation on concrete blocks with partial steel jackets, which endures axial compression. Experimental procedure provides the primary data for calibration of proposed model. Specimens have various steel jacketing ratios and the load is axial compression. The recorded data are strain components, elongation and the resisted force in experiment. A continuous cap plasticity surface expresses the non-uniform expansion and contraction of concrete beside an isotropic damage law that models the strength degradation using Abaqus® code. In presented mathematical model, the contraction and dilation of concrete is function of lateral pressure provided by steel jackets. The confining pressure is non-uniform due to discrete arrangement of steel ties in jacket and yielding of steel as concrete expands. Model provides parametric curves in order to design the confined-to-unconfined strength and ductility capacities of confined concrete. The presented numerical model is in close agreement with experimental results based on acquired results. We derive finally parametric curves for ductility and strength of confined concrete for various jacketing ratios.

Numerical and Experimental Investigations on the Low Velocity Impact Properties of Glass Fiber Reinforced Epoxy Composites: Effects of Radius of Curvature

Erfan Avazpoor,Amir Hossein Kazemian,Hossein Rahmani 한국섬유공학회 2023 Fibers and polymers Vol.24 No.9

This study was performed with the aim of investigating the Radius of Curvature Influence of glass fiber reinforced epoxy composites under Low Velocity Impact (LVI). Three different curvature radii of 10, 15, and 20 cm, as well as a sample with an infinite curvature radius (flat) of 9-ply laminated composite with woven roving glass fiber were employed for fabricating the specimens. Impact tests were performed using drop-weight impact device at different energy levels of 50, 100, and 150 J. Maximum force, absorbed energy, loading and unloading time, and damage area of the curved and flat composites laminated were evaluated. The results indicate that the absorption of energy increases with decreasing the curvature diameter, so that for sample D20, the amount of absorbed energy has increased on average 20%, for sample D15, 75% and for sample D10, 120% compared to the flat sample. Also the radius of curvature effects on peak load and loading and unloading times. Moreover, the low-velocity impact specifications of specimens were simulated using ABAQUS finite element software, and the results were compared with the experimental data.