Quantitative corrosion imaging of pipelines using multi helical guided ultrasonic waves

Dehghan-Niri, Ehsan,Salamone, Salvatore Techno-Press 2016 Structural monitoring and maintenance Vol.3 No.3

This paper presents a multi helical ultrasonic imaging approach for quantitative corrosion damage monitoring of cylindrical structures. The approach consists of two stages. First a multi helical ultrasonic imaging (MHUI) algorithm is used to provide qualitative images of the structure of interest. Then, an optimization problem is solved in order to obtain quantitative damage information, such as thickness map. Experimental tests are carried out on a steel pipe instrumented with six piezoelectric transducers to validate the proposed approach. Three thickness recesses are considered to simulate corrosion damage. The results show the efficiency of the proposed approach for quantifying corrosion location, area and remnant thickness.

Education for Intranational and International Understanding Awareness Building amongEducational Leaders and Educator in Madagascar

Hanitriniaina Niry Rakotomalal,Sungho Kwon(권성호) 한양대학교 교육공학연구소 2011 학습과학연구 Vol.5 No.2

나라와 나라간의 경계가 무의미해지고 지구촌으로 접어들고 있는 현시점에서, 다문화, 종교, 지역, 문화, 인종 사회에서는 그 어느 때보다 상대에 대한 이해력을 요구하고 있다. 교육을 통해 단순히 더불어 사는 것이 아닌 개인과 집단이 글로벌 시민으로서의 역량을 가지고, 대화를 주도해나가며, 참여 할 수 있도록 다른 문화와 인종, 신념에 대해서 배우는 것이 중요해지고 있다. 평화와 조화는 우리의 노력 없이 저절로 이루어지는 것이 아니다. 이 연구의 목적은 국내 외적 이해력(EIU)과 관련하여 지도자와 교육가, 그리고 학생들의 의식 수준을 향상시키는 것이다. 마다카스카의 중학교에서 실행된 APCEIU의 펠로위쉽을 통해 습득한 경험과 노력을 공유하고자 한다. 그리고 마다가스카 학교에 EIU 교육을 시작할 수 있도록 중학교를 중심으로 EIU 학습 활동을 개념화하고자 하였다. Today‘s national borders are becoming more and more permeable, and into a global village. The result of the globalization has been the creation of multi-ethnic, multi-cultural and multi-religious communities which require more demanding kinds of understanding. It is crucial that education would enhance knowledge of different cultures, peoples, beliefs and values that help individuals and communities not only to live together but also to be able to participate, to lead dialogues and to be equipped with the capacities to live a global citizen. Peace and harmony do not flow out from nowhere; these are ideals that we have to learn to build together. The objective of this study is to raise awareness of education leaders, educators and students in Madagascar on the relevance of E.I.U in both intranational and international context. We also aim at sharing inputs and experiences acquired through the fellowship at APCEIU with some secondary school teachers in Madagascar and conceptualize together with them basic E.I.U-related secondary school activities that they can use at once for a very first step toward E.I.U practice at Malagasy school.

Effect of hydraulic and structural parameters on the wave run-up over the berm breakwaters

Milanian, Farzad,Niri, Mahmood Zakeri,Najafi-Jilani, Ataollah The Society of Naval Architects of Korea 2017 International Journal of Naval Architecture and Oc Vol.9 No.3

The main aim of this study is to investigate the effect of berm breakwater on wave run-up. A total of 200 numerical analysis tests have been carried out in this paper to investigate the effect of berm width, wave height, and wave period on the wave run-up, using an integrating technique of Computer-Aided Design (CAD) and Computational Fluid Dynamics (CFD). Direct application of Navier Stokes equations within the berm width has been used to provide a more reliable approach for studying the wave run-up over berm breakwaters. A well tested Reynolds-averaged Navier-Stokes (RANS) code with the Volume of Fluid (VOF) scheme was adopted for numerical computations. The computational results were compared with theoretical data to validate the model outputs. Numerical results showed that the simulation method can provide accurate estimations for wave run-up over berm breakwaters. It was found that the wave run-up may be decreased by increasing the berm width up to about 36 percent. Furthermore, the wave run-up may increase by increasing the wave height and wave period up to about 53 and 36 percent, respectively. These results may convince the engineers to use this model for design of berm breakwater in actual scale by calculating the Reynolds numbers.

Simulating three dimensional wave run-up over breakwaters covered by antifer units

Najafi-Jilani, A.,Niri, M. Zakiri,Naderi, Nader The Society of Naval Architects of Korea 2014 International Journal of Naval Architecture and Oc Vol.6 No.2

The paper presents the numerical analysis of wave run-up over rubble-mound breakwaters covered by antifer units using a technique integrating Computer-Aided Design (CAD) and Computational Fluid Dynamics (CFD) software. Direct application of Navier-Stokes equations within armour blocks, is used to provide a more reliable approach to simulate wave run-up over breakwaters. A well-tested Reynolds-averaged Navier-Stokes (RANS) Volume of Fluid (VOF) code (Flow-3D) was adopted for CFD computations. The computed results were compared with experimental data to check the validity of the model. Numerical results showed that the direct three dimensional (3D) simulation method can deliver accurate results for wave run-up over rubble mound breakwaters. The results showed that the placement pattern of antifer units had a great impact on values of wave run-up so that by changing the placement pattern from regular to double pyramid can reduce the wave run-up by approximately 30%. Analysis was done to investigate the influences of surface roughness, energy dissipation in the pores of the armour layer and reduced wave run-up due to inflow into the armour and stone layer.

Effect of hydraulic and structural parameters on the wave run-up over the berm breakwaters

Farzad Milanian,Mahmood Zakeri Niri,Ataollah Najafi-Jilani 대한조선학회 2017 International Journal of Naval Architecture and Oc Vol.9 No.3

The main aim of this study is to investigate the effect of berm breakwater on wave run-up. A total of 200 numerical analysis tests have been carried out in this paper to investigate the effect of berm width, wave height, and wave period on the wave run-up, using an integrating technique of Computer-Aided Design (CAD) and Computational Fluid Dynamics (CFD). Direct application of Navier Stokes equations within the berm width has been used to provide a more reliable approach for studying the wave run-up over berm breakwaters. A well tested Reynolds-averaged NaviereStokes (RANS) code with the Volume of Fluid (VOF) scheme was adopted for numerical computations. The computational results were compared with theoretical data to validate the model outputs. Numerical results showed that the simulation method can provide accurate estimations for wave run-up over berm breakwaters. It was found that the wave run-up may be decreased by increasing the berm width up to about 36 percent. Furthermore, the wave run-up may increase by increasing the wave height and wave period up to about 53 and 36 percent, respectively. These results may convince the engineers to use this model for design of berm breakwater in actual scale by calculating the Reynolds numbers.

Landfill Site Selection using GIS and AHP: a Case Study: Behbahan, Iran

Zeinab Ghaed Rahmat,Mehdi Vosoughi Niri,Nadali Alavi,Gholamreza Goudarzi,Ali Akbar Babaei,Zeinab Baboli,Mohsen Hosseinzadeh 대한토목학회 2017 KSCE JOURNAL OF CIVIL ENGINEERING Vol.21 No.1

Finding a suitable site to dispose solid waste is a difficult task for municipality because it is necessary to consider the different factors and criteria in the landfill siting process. In this study, in order to consider all parameters, a combination of Geographic Information System (GIS) and the Analytic Hierarchy Process (AHP) was used for landfill site selection. For the purpose of making decisions in landfill site selection a hierarchy structural was formed and different parameters have been identified, including distance to groundwater, distance to surface water, sensitive ecosystems, land cover, distance to urban and rural areas, land uses, distance to roads, slope, soil type and distance to waste generation places. At first, the rating method was used to evaluate each criterion individually. Then, the relative importance of criteria to each other was determined by an analytic hierarchy process (AHP). Simple Additive Weighting (SAW) method was applied to evaluate the land suitability. The results showed that 38% of the study area have high suitability for land filling. Finally, five sites were a candidate for field investigation with more details.

Simulating three dimensional wave run-up over breakwaters covered by antifer units

A. Najafi-Jilani,M. Zakiri Niri,Nader Naderi 대한조선학회 2014 International Journal of Naval Architecture and Oc Vol.6 No.2

The paper presents the numerical analysis of wave run-up over rubble-mound breakwaters covered by antifer units using a technique integrating Computer-Aided Design (CAD) and Computational Fluid Dynamics (CFD) software. Direct application of Navier-Stokes equations within armour blocks, is used to provide a more reliable approach to simulate wave run-up over breakwaters. A well-tested Reynolds-averaged Navier-Stokes (RANS) Volume of Fluid (VOF) code (Flow-3D) was adopted for CFD computations. The computed results were compared with experimental data to check the validity of the model. Numerical results showed that the direct three dimensional (3D) simulation method can deliver accurate results for wave run-up over rubble mound breakwaters. The results showed that the placement pattern of antifer units had a great impact on values of wave run-up so that by changing the placement pattern from regular to double pyramid can reduce the wave run-up by approximately 30%. Analysis was done to investigate the influences of surface roughness, energy dissipation in the pores of the armour layer and reduced wave run-up due to inflow into the armour and stone layer.

A comprehensive study (kinetic, thermodynamic and equilibrium) of arsenic (V) adsorption using KMnO4 modified clinoptilolite

Mohamadreza Massoudinejad,Anvar Asadi,Mehdi Vosoughi Niri,Morteza Gholami,Babak Kakavandi,Mohammad Amin Karami 한국화학공학회 2015 Korean Journal of Chemical Engineering Vol.32 No.10

The sorption of As(V) on manganese oxide coated zeolite (MOCZ) was investigated through batch study to explore the feasibility of removing arsenic from groundwater. MOCZ was characterized by scanning electron microscopy, XRD, FTIR spectroscopy, and point of zero charge (pHPZC) measurements. The effects of process parameters such as contact time, adsorbent size, temperature and pH were investigated. Arsenic detection was carried out by atomic fluorescence spectrometer. Arsenate adsorption onto MOCZ followed the pseudo-second-order kinetic model with a correlation coefficient more than 0.99. Optimum removal of arsenate occurred within pH range of 6-10. The equilibrium data were analyzed by Langmuir, Freundlich and Dubinin-Radushkevich (D-R) isotherm models. The maximum adsorption capacity calculated from the Langmuir and D-R models was 151 and 152.8 μg g−1, respectively, at 38 oC. The activation energy of adsorption (Ea) was found to be 3.68 kj mol−1, suggesting that the adsorption process may be physical sorption. Thermodynamic parameters: ΔHo, was 1.181 kj mol−1; ΔSo, was −0.29 kj mol−1, while the values of ΔGo were −83.9, −86.7 and 89.8 kj mol−1 at 18, 28 and 38, respectively, suggesting endothermic and spontaneous process and a rise in temperature favoring the adsorption.

The adsorption of malachite green (MG) as a cationic dye onto functionalized multi walled carbon nanotubes

Amir Hossein Mahvi,Mohammad Shirmardi,Bayram Hashemzadeh,Abolfazl Naeimabadi,Ghasem Hassani,Mehdi Vosoughi Niri 한국화학공학회 2013 Korean Journal of Chemical Engineering Vol.30 No.8

Synthetic dyes are widely used by several industries to color their products. The discharge of colored wastewater into the hydrosphere causes serious environmental problems. We used functionalized multi wall carbon nanotubes as an adsorbent for the adsorption of cationic dye, malachite green, from aqueous solution. Based on information provided by the Iranian Research Institute of Petroleum Industry, carbon nanotubes are produced using a chemical vapor deposition (CVD) technique. These as-received MWCNTs were functionalized by acid treatment. The remaining dye concentration was read by UV-visible absorption spectroscopy at maximum adsorption wavelength. The effect of different operational parameters such as contact time, pH of solution, adsorbent dose and initial dye concentration were studied. The results showed that by increasing of contact time, pH and adsorbent dose the removal of dye increased,but by increasing initial dye concentration, the removal efficiency decreased. Adsorption isotherms and kinetics behavior of f-MWCNTs for removal of malachite green was analyzed, and fitted to various existing models. The experimental data were well correlated with the Langmuir isotherm with a maximum adsorption capacity (qm) and regression coefficient (R2) of 142.85 mg/g and 0.997, respectively. The results of this study indicate that functionalized multi wall carbon nanotubes can be used as an effective adsorbent for the removal of dyes.