Microstructure and Tensile Properties of Mg–5Zn Alloy Containing Ca

Elaheh Maleki,Farzad Shahri,Masoud Emamy 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.6

The present study aimed at investigating the effect of Ca (0–3 wt%) on the microstructure and tensile properties of as-castand as-extruded Mg–Zn alloy, in which tensile tests, X-ray diffraction, SEM, EDX and texture analysis were used to evaluatethese features. Based on the results obtained, it is shown that the average grain size decreased from 305 to 84 μm byadding 3 wt% Ca to the as-cast Mg–Zn alloy. XRD and SEM results reveal that the dominant second phase in the presenceof Ca is Ca2Mg6Zn3which is formed continuously between dendrite arms spacing. It has been observed that the additionof 0.1 wt% Ca, significantly enhanced both UTS and elongation of as-cast alloy. It is found that the size of DRXed grainsdecreases with the increase of Ca (4 μm with 3 wt% Ca addition) after hot-extrusion. Further, it has been observed thatUltimate tensile strength (UTS) and elongation values of extruded alloys containing Ca are enhanced and the best result isobtained for Mg–5Zn–0.1Ca sample. Ultimate tensile strength (UTS) of 351 MPa and elongation percentage of 24% areobtained for Mg–5Zn–0.1Ca extruded alloy.

The Effects of Teachers’ Written Comment Types and Iranian EFL Learners’ Attitudes

Elaheh Sotoudehnama,Maryam Molavi 아시아영어교육학회 2014 The Journal of Asia TEFL Vol.11 No.4

This study was designed to investigate the impact of teacher’s written feedback and the learners’ attitudes about it in the context of Iran. To this end, 60 intermediate-level learners of an institute participated in three 20 members groups, each group receiving one type of teacher’s written comments (i.e., imperatives, statements, and questions). The participants were asked to write four drafts on each of the two IELTS topics during a semester, and then a one-way ANOVA was conducted on the average gain scores from the first to the last drafts. The results showed that different feedback types can affect writing improvement differently, and statement feedback is the most effective comment for the context of this research. Moreover, the participants’ attitudes was investigated through using a questionnaire (adapted from Hamouda, 2011 & Beaumont et al., 2008), and statement feedback was reported as the most preferred comment type. Finally, correlations were conducted between the types of comments and the participants’ attitudes, the result of which indicated a match between the two results.

An improvement on fuzzy seismic fragility analysis using gene expression programming

Elaheh Ebrahimi,Gholamreza Abdollahzadeh,Ehsan Jahani 국제구조공학회 2022 Structural Engineering and Mechanics, An Int'l Jou Vol.83 No.5

This paper develops a comparatively time-efficient methodology for performing seismic fragility analysis of the reinforced concrete (RC) buildings in the presence of uncertainty sources. It aims to appraise the effectiveness of any variation in the material’s mechanical properties as epistemic uncertainty, and the record-to-record variation as aleatory uncertainty in structural response. In this respect, the fuzzy set theory, a well-known α-cut approach, and the Genetic Algorithm (GA) assess the median of collapse fragility curves as a fuzzy response. GA is requisite for searching the maxima and minima of the objective function (median fragility herein) in each membership degree, α. As this is a complicated and time-consuming process, the authors propose utilizing the Gene Expression Programming-based (GEP-based) equation for reducing the computational analysis time of the case study building significantly. The results indicate that the proposed structural analysis algorithm on the derived GEP model is able to compute the fuzzy median fragility about 33.3% faster, with errors less than 1%.

Synthesis and comparison of MgAl2O4-Ti [C, N] composites using aluminothermic-carbothermal reduction and molten salts routes

Elaheh Khosh Omid,Rahim Naghizadeh,Hamid Reza Rezaie 한양대학교 세라믹연구소 2013 Journal of Ceramic Processing Research Vol.14 No.4

MgAl2O4-Ti (C, N) composites were synthesized through aluminothermic-carbothermal reduction and molten salts synthesis (MSS) routes in coke bed conditions. The phases were characterized using X-ray diffraction (XRD) and microstructures of composites were investigated by scanning electron microscopy (SEM). The results showed that the synthesis temperature of MgAl2O4-Ti (C, N) was decreased about 300 o C in MSS method in comparison with aluminothermic-carbothermal reduction. The KCl and NaCl salts proved better transportation path for reactant species and accelerate composite formation and also establish the microstructure with homogenous and fine grains.

An Efficient Approach based on Genetic Algorithm for multi-tenant Resource Allocation in SaaS Applications

Elaheh Kheiri,Mostafa Ghobaei Arani,Reyhaneh Kheiri,Alireza Taghizadeh 보안공학연구지원센터 2016 International Journal of Software Engineering and Vol.10 No.8

In recent years, the use of cloud services has been significantly expanded. The providers of software as a service employ multi-tenant architectures to deliver services to their users. In these multi-tenant applications the resource allocation would suffer from over-utilization or under-utilization issues. Considering the significant effects of resource allocation on the service performance and cost, in this paper we have proposed an approach based on genetic algorithm for resource allocation which guarantees service quality through providing adequate resources. The proposed approach also improves system performance, meets the requirements of users and provides maximum resource efficiency. Simulation results show that the proposed approach has better response rate and availability comparing to other approaches, while provides an efficient resource usage.

Fe3O4/SiO2 nanoparticles coated with polydopamine as a novel magnetite reductant and stabilizer sorbent for palladium ions: Synthetic application of Fe3O4/SiO2@PDA/Pd for reduction of 4-nitrophenol and Suzuki reactions

Elaheh Farzad,Hojat Veisi 한국공업화학회 2018 Journal of Industrial and Engineering Chemistry Vol.60 No.-

Polydopamine (PDA)-coated Fe3O4/SiO2 nanoparticles (Fe3O4/SiO2@PDA) were synthesized through a simple and green procedure. In this study, for the first time, successful deposition of Pd nanoparticles is described by using Fe3O4/SiO2@PDA as a magnetic reducing and stabilizing agent. In this approach, palladium ions were adsorbed on Fe3O4/SiO2@PDA surfaces by immersing the PDA-coated Fe3O4/SiO2 nanoparticles into a palladium plating bath. Then, they were reduced in situ to palladium nanoparticles by the help of PDA’s N-containing groups and reducing ability. The structure, morphology and physicochemical properties of the synthesized particles were characterized by different analytical techniques such as high resolution transmission electron microscopy (HRTEM), field emission scanning electron microscope (FESEM), energy-dispersive X-ray spectroscopy (EDS), wavelength-dispersive X-ray spectroscopy (WDX), X-ray diffraction analysis (XRD), vibrating sample magnetometer (VSM), X-ray photoelectron spectroscopy (XPS), inductively coupled plasma (ICP) and FT-IR spectroscopy. Fe3O4/SiO2@PDA/Pd nanoparticles illustrated high catalytic activity as a recyclable nanocatalyst in Suzuki–Miyaura cross-coupling reactions and reduction of 4-nitrophenol (4-NP), at room temperature. Furthermore, recovery and multiple reuse of the catalyst revealed no detectable activity loss.

An updated review on therapeutic effects of nanoparticle-based formulations of saffron components (safranal, crocin, and crocetin)

Elaheh Mirhadi,Hooriyeh Nassirli,Bizhan Malaekeh‑Nikouei 한국약제학회 2020 Journal of Pharmaceutical Investigation Vol.50 No.1

In recent years, nanotechnology has come to help researchers a lot in different fields. Especially in medicine and drug delivery, it presents new methods and technologies to increment levels of drug delivery to tumors and decrement side effects of drugs and molecules. Saffron, the dried stigma of the flower of the Crocus sativus plant, is one of the most widely used types of spice with many therapeutic applications that are related to its components: crocin, crocetin, and safranal. Saffron has been used as antispasmodic, anticatarrhal, eupeptic, nerve sedative, gingival sedative, diaphoretic, expectorant, carminative, stomachic, stimulant, emmenagogue, and aphrodisiac for years and now it has been made clear that it could have antioxidant, antidepressant, and anti-cancer activity. This review discusses how nanotechnology could help improve saffron’s pharmaceutical effects and makes it more functional in treatment.

Adsorptive separation of CO2 and CH4 by the broom sorghum based activated carbon functionalized by diethanolamine

Elaheh Mehrvarz,Ali Asghar Ghoreyshi,Mohsen Jahanshahi 한국화학공학회 2017 Korean Journal of Chemical Engineering Vol.34 No.2

A low-cost activated carbon (AC) was produced from the broom sorghum stalk using KOH as the chemical activating agent, and then the surface of AC was functionalized with diethanolamine to enhance CO2/CH4 selectivity. Characteristics of pristine and DEA-functionalized ACs were determined through different analyses such as Boehm’s method, BET, FT-IR, SEM, and TGA. The adsorption behavior of pure carbon dioxide and pure methane on these adsorbents was investigated in a temperature range of 288-308 K and pressure range of 0-25 bar using an apparatus based on a volumetric method. Results indicated that amine functionalization significantly improved the selectivity of CO2/CH4. The enhancement of CO2 ideal adsorption selectivity over CH4 from 1.51 for the pristine AC to 5.75 for the AC-DEA was attributed to adsorbate-adsorbent chemical interaction. The present DEA-functionalized AC adsorbent can be a good candidate for applications in natural gas and landfill gas purifications.

A novel radiofrequency modulation therapy versus routine physiotherapy modalities in treatment of myofascial pelvic pain syndrome: a pilot randomized trial

( Elaheh Miri Ashtiani ),( Nasim Shokouhi ),( Mona Mohseni ),( Nafiseh Saedi ),( Ali Asghar Haeri-mehrizi ),( Mahmood Bakhtiyari ) 대한산부인과학회 2023 Obstetrics & Gynecology Science Vol.66 No.3

Objective The current study aimed to compare the effectiveness of novel radiofrequency modulation (RM) therapy with a tailored physiotherapy course for patients with chronic pelvic pain (CPP) of myofascial origin, also known as myofascial pelvic pain syndrome (MPPS). Methods We enrolled 46 patients with myofascial CPP to compare the effectiveness of a 10-session routine physiotherapy course versus a 6-session RM with an integrated device (HIGGS) in alleviating MPPS morbidity and pelvic floor muscle (PFM) rehabilitation. The primary outcome was reduction in pelvic pain after the final session and in the follow-up period 3 months after the final intervention session. Results The 6-session therapy in the RM group and the manual, biofeedback, and transcutaneous electrical nerve stimulation therapies in the physiotherapy group were similarly effective in reducing pain and improving PFM endurance after the final intervention session in each group, whereas perineometer readings and PFM strength were associated with greater improvements in the physiotherapy group. Conclusion The results of this study demonstrated comparable effectiveness of RM in the management of MPPS and improvement of PFM function compared to routine physiotherapy programs with fewer sessions of therapy.

Positive Interaction Between CG, CC Genotypes of Cryptochrome Circadian Clocks 1, and Energy-Adjusted Dietary Inflammatory Index on High Sensitivity C-Reactive Protein Level in Women With Central Obesity

Elaheh Asgari,Farideh Shiraseb,Atieh Mirzababaei,Hadith Tangestani,Khadijeh Mirzaei 한국임상영양학회 2023 Clinical Nutrition Research Vol.12 No.1

Creating a complex balance between dietary composition, circadian rhythm, and the hemostasis control of energy is important for managing diseases. Therefore, we aimed to determine the interaction between cryptochrome circadian clocks 1 polymorphism and energy-adjusted dietary inflammatory index (E-DII) on high-sensitivity C-reactive protein in women with central obesity. This cross-sectional study recruited 220 Iranian women aged 18–45 with central obesity. The 147-item semi-quantitative food frequency questionnaire was used to assess the dietary intakes, and the E-DII score was calculated. Anthropometric and biochemical measurements were determined. By polymerase chain response-restricted length polymorphism method, cryptochrome circadian clocks 1 polymorphism was assigned. Participants were categorized into three groups based on the E-DII score, then categorized according to cryptochrome circadian clocks 1 genotypes. The mean and standard deviation of age, BMI, and high-sensitivity C-reactive protein (hs-CRP) were 35.61 ± 9.57 years, 30.97 ± 4.16 kg/m2 , and 4.82 ± 5.16 mg/dL, respectively. The interaction of the CG genotype and E-DII score had a significant association with higher hs-CRP level compared to GG genotype as the reference group (β, 1.19; 95% CI, 0.11–2.27; p value, 0.03). There was a marginally significant association between the interaction of the CC genotype and the E-DII score with higher hs-CRP level compared to the GG genotype as the reference group (β, 0.85; 95% CI, −0.15 to 1.86; p value, 0.05). There is probably positive interaction between CG, CC genotypes of cryptochrome circadian clocks 1, and E-DII score on the high-sensitivity C-reactive protein level in women with central obesity.