S, P-codoped rGO-phytic acid-polythiophene core–shell; synthesis, modeling, and dual active–passive anti-corrosion performance of epoxy nanocomposite

Mohammad Ebrahim Haji Naghi Tehrani,Mohammad Ramezanzadeh,Ghasem Bahlakeh,Bahram Ramezanzadeh 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.103 No.-

In this study, a novel anticorrosive pigment is introduced to fabricate a smart epoxy coating with biactive/passive protection capabilities. For this purpose, the dual functionalized S, P-doped graphene oxide(GO) structure was synthesized through the rationed devised approach using phytic acid and polythiophene. The thiophene monomer was successfully polymerized on the modified rGO-Phytic acid (rGOPhy)sheets. It was observed that the polythiophene nano-scale particles well decorated the rGO-Phy surface,which was proved via Raman, FT-IR, UV–Vis, SEM-EDS, XRD, and TGA analyses. The developed nanocompositeswere also introduced into the epoxy coating for anti-corrosive purposes. The corrosion retardationperformance of the exerted coatings on the mild steel panels shows that the rGO-Phytic acid-Polythiophene (rGO-Phy-Pth) nano-composites inclusion into the epoxy composite coating endows theself-healing performance in line with the extraordinary barrier feature bring about the stable protectionfor almost 9 weeks. The achieved outstanding self-healing potential is assigned to the simultaneous controlledrelease of the polythiophene and phytic acid at the damaged area from the GO sheets, resulting ina film formation with increasing the resistance up to 50 kX cm2 while the blank sample demonstratedthe decreasing trend.

A highly-effective/durable metal-organic anti-corrosion film deposition on mild steel utilizing Malva sylvestris (M.S) phytoextract-divalent zinc cations

Mohammad Ebrahim Haji Naghi Tehrani,Mohammad Ramezanzadeh,Bahram Ramezanzadeh 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.95 No.-

For thefirst time, a metal-organicfilm with high anti-corrosion potency was constructed over the mildsteel surface using Malva sylvestris (M.S) and zinc cations (Zn2+). The mild steel panels were immersed inthe simulated seawater solution (3.5%wt. NaCl solution) containing different loadings of Zn:M.Sinhibitors. The electrochemical impedance spectroscopy (EIS) and open circuit potential (OCP)measurements were performed at a different time step up to 240 h. The potentiodynamic polarizationtest was carried out to determine the inhibitor's inhibition mechanisms. The synergistic inhibitionimpact of the Zn:M.S before and after immersion was analyzed by Ultraviolet-Visible (UV–vis)spectroscopy. The protectivefilm formed on the surface was studied by the Fourier transform infrared(FT-IR), Raman, grazing incidence X-ray diffraction (GIXRD), scanning electron microscopy-energydispersive spectroscopy (SEM-EDS), atomic force microscopy (AFM), and contact angle (CA) techniques. The EIS results evidenced that applying various ratios of Zn:M.S resulted in more than 98% corrosioninhibition efficiency (IE), which was stable up to 240 h. Meanwhile, the outstanding corrosion resistanceof 170 kV.cm2 in 300:700 ppm Zn:M.S was recorded.

SIP Flooding Attacks Detection and Prevention Using Shannon, Renyi and Tsallis Entropy

Reihaneh Haji Mahdizdeh Zargar,Mohammad Hossein Yaghmaee Moghaddam 보안공학연구지원센터 2014 International Journal of Hybrid Information Techno Vol.7 No.5

MAPS PRESERVING η-PRODUCT A*B + ηBA* ON C*-ALGEBRAS

Vahid Darvish,Haji Mohammad Nazari,Hamid Rohi,Ali Taghavi 대한수학회 2017 대한수학회지 Vol.54 No.3

Let $\mathcal{A}$ and $\mathcal{B}$ be two $C^{*}$-algebras such that $\mathcal{A}$ is prime. In this paper, we investigate the additivity of maps $\Phi$ from $\mathcal{A}$ onto $\mathcal{B}$ that are bijective and satisfy $$\Phi(A^{*}B+\eta BA^{*})=\Phi(A)^{*}\Phi(B)+\eta \Phi(B)\Phi(A)^{*}$$ for all $A, B\in \mathcal{A}$ where $\eta$ is a non-zero scalar such that $\eta\neq \pm1$. Moreover, if $\Phi(I)$ is a projection, then $\Phi$ is a $\ast$-isomorphism.

Combined Use of Sewage Sludge Ash and Silica Fume in Concrete

Fazel Azarhomayun,Mohammad Haji,Mahdi Kioumarsi,Ali Kheyroddin 한국콘크리트학회 2023 International Journal of Concrete Structures and M Vol.17 No.5

The lack of adequate space for sewage sludge disposal has become a significant challenge in many countries. Landfilling and using sewage sludge as fertilizer in agricultural lands are the main methods for disposal. However, these methods can result in soil and groundwater contamination as well as heavy metal and microbial pollution in soil. An alternative disposal method is using sewage sludge ash (SSA) in concrete production. If the sludge ash is reactive, it can replace a portion of cement in concrete; otherwise, it can be used as a filler. In the present study, X-ray fluorescence (XRF) experiments were conducted to determine the elemental composition of sewage sludge. Then, the sewage sludge was incinerated, and XRF and X-ray diffraction (XRD) tests were performed on the resulting sewage sludge ash. The ash was utilized in different proportions in the mortar and concrete specimens, and compressive strength tests were conducted on the resulting specimens. The results indicate that using 20% SSA instead of cement resulted in a 25% reduction in compressive strength in concrete specimens. However, the combination of 10% silica fume and 10% SSA was the optimal combination to compensate for the reduction in compressive strength caused using SSA.

Design equations for prefabricated steel moment connections

Seyed Morteza Kazemi,Mohammad Reza Sohrabi,Hasan Haji Kazemi 국제구조공학회 2021 Structural Engineering and Mechanics, An Int'l Jou Vol.80 No.3

Recently, modular prefabricated steel moment connections have been widely studied by several researchers. These connections are made of tubular columns that are ended to horizontal plates at both sides, an inter-story short column, and truss beams that are joined to the connecting plates using top and bottom plates. In this study, a series of equations have been developed and presented for designing each component of this type of connection. Then, to verify the proposed equations, the connection was modeled in ABAQUS and then the results extracted from the equations and modeling were compared. The findings indicated that the proposed equations have the required accuracy.

Application of a Network Scale-up Method to Estimate the Size of Population of Breast, Ovarian/Cervical, Prostate and Bladder Cancers

Haghdoost, Ali Akbar,Baneshi, Mohammad Reza,Haji-Maghsoodi, Saeedeh,Molavi-Vardanjani, Hossein,Mohebbi, Elham Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.8

Network scale up (NSU) is a novel approach to estimate parameters in hard to reach populations through asking people the number of individuals they know in their active social network. Although the method have been used in hidden populations, advantages of NSU indicate that exploration of applicability to disease like cancer might be feasible. The aim of this study was to assess the application of NSU to estimate the size of the population of breast, ovarian/cervical, prostate, and bladder cancers in the South-east of Iran. A total of 3,052 (99% response rate) Kermanian people were interviewed in 2012-2013. Based on NSU, participants were asked about if they know any people on their social network who suffered from breast, ovarian/cervical, prostate, and bladder cancers, if yes, they should enumerate them. A total of 1,650 persons living with four types of cancers (breast, ovary/cervix, prostate, and bladder) were identified by the respondents. Totally, the prevalence of people living with the four types of cancers was 228.4 per 100,000 Kermanian inhabitants. The most prevalent cancer was breast cancer, at 168.9 per 100,000, followed by prostate cancer with 116.9, ovarian/cervical cancer with 99.8, and bladder cancer with 36.3 per 100000 Kerman city population. NSU values provide a usable but not very precise way of estimating the size of subpopulations in the context of the four major cancers (breast, ovary/cervix, prostate, and bladder).

The removal of Cr(VI) from aqueous and saturated porous media by nanoscale zero-valent iron stabilized with flaxseed gum extract: Synthesis by continuous flow injection method

Neman Izadi,Banafsheh Haji Ali,Mohammad Sajjad Shahin,Majid Baghdadi 한국화학공학회 2022 Korean Journal of Chemical Engineering Vol.39 No.8

Recently, the in-situ removal of contaminants by iron nanoparticles has been considered due to their nontoxicity,abundance, ease of production, and cost-effectiveness, which can be accomplished by injecting them underground. In this study, nZVI was synthesized using a novel continuous synthesis method using flaxseed glaze as a green,non-toxic, and low-priced coating. The produced nanoparticles were characterized by dynamic diffraction analysis(DLS), field electron microscopy (FE-SEM), X-ray spectroscopy (EDX), and infrared spectroscopy (FTIR) spectroscopy. Batch experiments were conducted to evaluate the effect of Cr(VI) concentration, FG-nZVI dosage, pH, and coexistingcomponents (Total dissolved solids, Humic acid, and NO3) on Cr(VI) removal. Results of the characterization andidentification, and stability tests indicated that nanoparticles synthesized by using this continuous synthesis system weresmaller and more regular shaped than those prepared by conventional synthesis. According to the results, the Cr(VI)residual level increased by increasing the initial Cr(VI) concentration and decreased by increasing the nZVI coatedwith flaxseed glaze (FG-nZVI) dosage. At the Cr(VI) initial concentration of 4mg L1, the Cr(VI) was removed entirelyat almost all dosages of FG-nZVI. Optimal amount of FG-nZVI was 62.73mg L1 when applied at 4mg L1 of Cr(VI)at optimum pH 6.64, resulting in the Cr(VI) residual concentration of 0.05mg L1. The results of saturated porousmedia showed that injection background solutions enhanced the transfer of nanoparticles in the porous medium, resultingin the adequate removal along the desired radius. The results illustrated that using FG-nZVI can be effective forpractical groundwater remediation.

Experimental study of collapse mode and crashworthiness response of tempered and annealed aluminum tubes under axial compression

Majid Emadi,Hamid Beheshti,Mohammad Heidari-Rarani,Farhad Haji Aboutalebi 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.5

Thin-walled aluminum tubes have been widely used in engineering structures, aerospace and transportation industries due to their excellent properties. In this paper, the effect of tempering and annealing on the crushing behavior of aluminum alloy tubes, in brittle or ductile manner, under quasi-static compression were investigated. The chemical composition, the Brinell hardness number and the tensile stress-strain curves of various types of Al alloys, i.e., Al 2024, Al 7075 and Al 6061 were obtained in both tempered and annealed state. Then, the axial compression tests were performed on the tubes by a universal testing machine at a controlled displacement rate of 5 mm/min. The crushing mode, load-displacement curve, and crashworthiness characteristics were achieved to obtain specifications of mentioned aluminum tubes. Annealing process, apart from changing the deformation mode and material strength, has often reduced energy absorption in the ductile alloy, Al 6061, and increased in brittle alloys, Al 2024-T3, T4 and Al 7075-T651. This process could also be used as a triggering mechanism to decrease the initial peak force. These experimental results give useful information regarding the material behavior of aluminum alloys to be utilized in the design process of crashworthy components.

Evaluation the behavior of pre-fabricated moment connection with a new geometry of pyramidal end block under monotonic and cyclic loadings

Seyed Morteza Kazemi,Mohammad Reza Sohrabi,Hasan Haji-Kazemi 국제구조공학회 2018 Steel and Composite Structures, An International J Vol.29 No.3

Researchers have been long studying new building implementation methods to improve the quality of construction, reduce the time of assembly, and increase productivity. One of these methods is the use of modular pre-fabricated structural forms that are composed of a beam, column, short column, pyramidal end block, and connection plates. In this study, a new geometry for the pyramidal end block was proposed that helps facilitate the assembly procedure. Since the proposed configuration affects the performance of this form of connection, its behavior was evaluated using finite element method. For this purpose, the connection was modeled in ABAQUS and then validated by comparing the outputs with experimental results. The research proceeded through analyzing 16 specimens under monotonic and cyclic loading. The results indicated that using the pyramidal end block not only makes the assembly process easier but also reduces the out-of-plane displacement of the short column webs and the vertical displacement of beam end. By choosing appropriate section properties for column and beam, the connection can bear a rotation up to 0.01 radians within its inelastic region and a total of 0.04 radians without any significant reduction in its bearing capacity.