15 research outputs found
Factors Underlying characteristics of acquisition of English language in EFL classrooms
This study tries to find what factors underline the characteristics of acqusition of English language in EFL classrooms. The questionnaire addressing the Characteristics of English Language Acqusition Scale ( ELAS) and consisting of 41 closed questions was designed by the researchers of this study and was administered to 388 pre University Iranian EFL students at various private and public schools in Neyshabour ,Zebarkhan, to test the number of extracted factors and their cross loading . The 41 characteristics loaded on twelve rotated factors when the Principle Axis Factoring was applied to the participants' responses i.e., Learning boosters, facilitation, determination, voluntary, teaching methodology, affective factors, attitudes toward foreign speakers and their culture, learner engagement, adjustment, enhancement, teachers'output and individual differences
Language Acquisition and English Achievement at Grade Four Senior High School
This study aimed to explore the relationship between language acquisition and grade four senior high school (G4SHS) students’ achievement in English as a foreign language (EFL). To this end the 41-item English Language Acquisition Scale (ELAS) designed by Khodadady and Younesi (2017) was administered to 518 G4SHS students. Also to find the probable relationship between ELAS, its latent variables and participant achievement in EFL classes in EFL classes 126 participants were randomly selected out of population to answer schema-based cloze multiple choice items test ( S- test) designed by Khodadady and Ghergloo ( 2013). To know which of the G4SHS students who took the ELAS took the S-Test as well the researcher was matched the codes of the ELAS S-test and ELTAS carefully. The results showed that the ELAS consists of five factors, i.e., Qualified, grammatization, Humanistic, Engagement and Orientation. Also the ELAS and its underlying factors show significant relationships with English achievement scores. The results of the study are discussed
Color Doppler sonography of the aortic isthmus in intrauterine growth-restricted fetuses and normal fetuses
Intrauterine growth restriction is associated with a significant increase in morbidity and perinatal mortality, and increases the likelihood of fetal death, asphyxia, meconium aspiration, hypoglycemia, and neonatal hypothermia. The aim of this study was to determine aortic isthmus flow difference by using color doppler sonography in Intrauterine growth restriction and normal fetuses. The data presented were obtained from 30 mothers, who referred to the radiology department of Akbarabadi Hospital of Tehran with a diagnosis of intrauterine growth restriction. An ultrasound was performed to determine the status of placenta, fetus, and amniotic fluid. The umbilical arterial doppler assessment was used to confirm diagnosis of intrauterine growth restriction. Thirteen (43.3%) were nulliparous mothers and 17 (56.7%) were multiparous mothers. 30 pregnant women with healthy fetuses were enrolled as control group. According to the ultrasound findings, Dactus Venus wave type was recorded in intrauterine growth restriction fetuses, which was reported as normal (26 subjects; 86.7%) and abnormal (4 subjects; 13.3%). All together, this study provides appropriate guidance to use doppler for delivery timing and to control risk factors
A smart load-speed sensitive cooling map to have a high- performance thermal management system in an internal combustion engine
Considering the fact that electrification is increasingly used in internal combustion engines, this paper aims at presenting a smart speed-load sensitive cooling map for better thermal management. For this purpose, first, thermal boundary conditions for the engine cooling passage were obtained by thermodynamic and combustion simulation. Next, the temperature distribution of the cooling passage walls was determined using conjugate heat transfer method. Then, the effect of engine load on wall temperature distribution was investigated, and it was observed that in the conventional mode where the cooling flow is only affected by the engine speed, the engine is faced with over-cooling and under-cooling. Therefore, the optimum flow for cooling the engine was achieved in such a way that the engine is hot enough and kept free from damage, while the engine has a more uniform temperature distribution. These calculations were performed by considering the boiling phenomenon. The results showed using the cooling map leads to a significant reduction in coolant flow, which in turn reduces the power consumption of the water pump and size of the radiator. Moreover, fuel consumption, hydrocarbon emission production, and the needed power of the coolant pump are enhanced by 2.1, 8.6, and 44.3%, respectively.Irankhodro Powertrain Company (IPCo)http://www.elsevier.com/locate/energy2022-04-22hj2021Mechanical and Aeronautical Engineerin
Dionysia robusta (Primulaceae), a new species from W Iran
A new species from the W part of the Iranian Zagros Mountains in Ilam province, Dionysia robusta (Primulaceae), is described, illustrated and compared with similar and related species. It differs from these relatives in leaf shape, length and density of glandular hairs, and shape of the calyx. The DNA sequence of the nuclear ribosomal ITS region of D. robusta is most similar to that of D. gaubae
Application of proton-conducting sulfonated polysulfone incorporated MIL-100(Fe) composite materials for polymer-electrolyte membrane microbial fuel cells
This research aimed to evaluate a microbial fuel cell (MFC) device equipped with a novel composite polymer-electrolyte membrane consisting of the metal-organic framework and sulfonated polysulfone (SPSU/MIL-100(Fe)) for simultaneous treatment of meat poultry wastewater and power generation. The composite SPSU/MIL-100(Fe) membranes were fabricated by solution casting of polymer and characterized to determine the MFC performance. A 20 wt% SPSU solution with 42.27%desulfonation degree exhibited an IEC 1.2 meq g−1, PC 0.90 mS cm−1, and low WU 7%. However, the minimum oxygen diffusion coefficient 1.23 × 10−5 cm2 s−1, oxygen mass transfer coefficient 6.49 × 10−4 cm s−1, maximum PC 2.55 mS cm−1, and WU 36.50% were achieved with SPSU composite membrane by loading 7% MIL-100(Fe), denoted as SPSU/MIL7. The MFC with the as-synthesized SPSU/MIL7 composite membrane for application of poultry wastewater treatment was tested and compared to that achieved with Nafion. The SPSU/MIL7 membrane with voltage 970 mV, power density 27.60 mW m−2, PC 2.55 mS cm−1, and CE 31.01% revealed higher MFC achievement. Moreover, under the same condition, slightly higher COD removal (57.65%) is observed in the MFC with SPSU/MIL7 membrane than with Nafion117 (55.02%). The results firmly suggest that SPSU/MIL7, as a promising MOF separator, finds application in proton exchange membrane MFCs (PEMMFCs)
Incorporating sulfonated MIL-100(Fe) in sulfonated polysulfone for enhancing microbial fuel cell performance
This study aims to synthesize a proton exchange membrane (PEM) by incorporating a sulfonated MIL-100(Fe) metal–organic framework (sMILFe MOF) into the sulfonated polysulfone (sPSf), to investigate the maximum capability of microbial fuel cells (MFCs) in organic degradation and electricity generation. The physicochemical properties of the membranes, such as water uptake (WU), ion exchange capacity (IEC), proton conductivity (PC), coulombic efficiency (CE), and performance of MFC with sPSf incorporated with unsulfonated MIL-100(Fe) MOF (sPSf/MILFe), and sulfonated MIL-100(Fe) MOF (sPSf/sMILFe) composite membranes were compared. The prepared (sPSf/sulfonated MIL100(Fe)) membrane showed improved PC of the sPSf membrane and revealed the peak output of power energy of 64.2 mW m−2 in mixed liquor suspended solid (MLSS) concentration 4000 mg L−1, as compared to 29.8 mW m−2 and 50.8 mW m−2 obtained for sPSf, sPSf/MILFe membranes, respectively, in two-chambered MFCs. Furthermore, this composite membrane delivered a higher PC of 40.6 mW m−2 compared to Nafion-117 in the MFC. The remarkably enhanced performance of the composite electrolyte membranes was due to the added sulfonated MIL-100(Fe), which provided effective proton-conducting channels for proton transport in the membrane matrix. Integrating sulfonated polysulfone chains into open channels enables vehicular and Grotthuss (proton hopping) mechanisms across the channels, considerably enhancing PC and coulombic efficiencies
Projection of Environmental Pollutant Emissions From Different Final Waste Disposal Methods Based on Life Cycle Assessment Studies in Qazvin City
In the current study, the life cycle assessment (LCA) method was used to expect the emissions of different environmental pollutants through qualitative and quantitative analyses of solid wastes of Qazvin city in different final disposal methods. Therefore, four scenarios with the following properties considering physical analysis of Qazvin’s solid wastes, the current status of solid waste management in Iran, as well as the future of solid waste management of Qazvin were described. In order to detect the quantity of the solid wastes, the volume-weighted analysis was used and random sampling method was used for physical analysis. Of course, regarding the method of LCA, it contains all stages from solid wastes generation to its disposal. However, since the main aim of this study was final disposal stage, the emissions of pollutants of these stages were ignored. Next, considering the mixture of the solid waste, the amount of pollution stemming from each of final disposal methods from other cities having similar conditions was estimated. The findings of the study showed that weight combination of Qazvin solid wastes is entirely similar to that of other cities. Thus, the results of this study can be applied by decision makers around the country. In scenarios 1 and 2, emission of leachate containing high amounts of COD and BOD is high and also the highest content of nitrate, which can contaminate water and soil resulting in high costs for their management. In scenarios 3 and 4, the amounts of gaseous pollutants, particularly CO2, as well as nitrogen oxides are very high. In conclusion, the LCA methods can effectively contribute to the management of municipal solid wastes (MSW) to control environmental pollutants with least expenses
Bioremediation by MFC technology
As the world gears up for the Net Zero carbon emissions, demand for raw materials is set to skyrocket as they are key elements of global economy and they have essential roles in improvement of life quality and the performance of manufacturing productivity. The various conventional treatment methods, including physical, chemical, and biological processes, may become outdated and may generally be restricted due to associated disadvantages such as high initial capital cost, chemical requirements, and sludge generation. Bioelectrochemical systems (BESs) have the potential to overcome these disadvantages and produce renewable energy from wastewater or recover precious metals from waste. In BESs processes, chemical energy is converted into electrical energy from the oxidation of waste using electrogenic biocatalysts. Microbial electrochemical systems (MESs) can result in interactions between microorganisms, metals, and electrodes, in which the electron transfer chain associated with both aerobic and anaerobic microbial respiration can play a critical role to overcome these challenges. This chapter summarizes the studies conducted on the various BES processes, namely microbial fuel cells (MFCs), anaerobic microbial fuel cells (ANMFCs), sediment microbial fuel cells (SMFCs), benthic microbial fuel cells (BMFCs), and thermophilic microbial fuel cells (TMFCs), to treat wastewater rich in heavy metals. We document the state of the art concerning various BES applications and emphasize that organic waste can be eliminated as an electron donor via microbe-catalyzed oxidization at the anode and metals recovered at the cathode as electron acceptors through reduction