Important Factors on the Failure of Pipeline Steels with Focus on Hydrogen Induced Cracks and Improvement of Their Resistance: Review Paper

M. A. Mohtadi‑Bonab,H. Ghesmati‑Kucheki 대한금속·재료학회 2019 METALS AND MATERIALS International Vol.25 No.5

Currently, thousands of kilometers of pipeline steels are transferring hydrocarbon fluids such as oil and natural gas in theworld. Due to the fact that these pipes transport corrosive and high-pressure fluids from harsh environments, they are damagedand eventually degraded. Previous studies showed that sulphide stress cracking, hydrogen induced cracking (HIC) andstress corrosion cracking are the main destructive factors in these types of pipes. This paper focused on the HIC related failurein pipeline steel, since the role of texture and grain boundary character has not been completely recognized. Moreover, ifpipeline damage is occurred by hydrogen cracks, besides the environmental pollutions, it will cost a lot to repair or replacethe damaged pipeline steels. In this research, the factors influencing the initiation and propagation of the HIC cracks, suchas hydrogen traps, inclusions, precipitates, microstructure and texture of steel have been investigated. Also, the existingsolutions for improving the steel resistance to the HIC have been investigated based on the control of micro-alloy elements,texture and grain boundary engineering. For instance, some special dominant texture components and coincidence site latticeboundaries decrease the HIC susceptibility by providing the resistant path for crack propagation.

Effect of Different Microstructural Parameters on Hydrogen Induced Cracking in an API X70 Pipeline Steel

M. A. Mohtadi-Bonab,M. Eskandari,R. Karimdadashi,J. A. Szpunar 대한금속·재료학회 2017 METALS AND MATERIALS International Vol.23 No.4

In this study, the surface and cross section of an as-received API X70 pipeline steel was studied by SEM and EDStechniques in order to categorize the shape and morphology of inclusions. Then, an electrochemical hydrogencharging using a mixed solution of 0.2 M sulfuric acid and 3 g/l ammonium thiocyanate has been utilized to createhydrogen cracks in X70 steel. After hydrogen charging experiments, the cross section of this steel has been accuratelychecked by SEM in order to find out hydrogen cracks. The region of hydrogen cracks was investigated bySEM and EBSD techniques to predict the role of different microstructural parameters involving hydrogen inducedcracking (HIC) phenomenon. The results showed that inclusions were randomly distributed in the cross section oftested specimens. Moreover, different types of inclusions in as-received X70 steel were found. However, onlyinclusions which were hard, brittle and incoherent with the metal matrix, such as manganese sulfide and carbonitrideprecipitates, were recognized to be harmful to HIC phenomenon. Moreover, HIC cracks propagate dominantlyin transgraular manner through differently oriented grains with no clear preferential trend. Moreover, adifferent type of HIC crack with about 15-20 degrees of deviation from the rolling direction was found and studiedby EBSD technique and role of micro-texture parameters on HIC was discussed.

Spatiotemporal Gait Parameters and Gait Asymmetry in Patients With Lumbar Disc Herniation, Treated With Microdiscectomy: A Prospective, Observational Study

Masoud Amir Rashedi Bonab,Suleyman Sener,Tugba Kuru Colak,Mahsa Amirrashedi,Ipek Yeldan,Deniz Konya,Zafer Orkun Toktas 대한척추신경외과학회 2023 Neurospine Vol.20 No.3

Objective: The aim of this study was to emphasize on the interaction of spatial and temporal gait parameters and analyse the gait asymmetry in the patients with lumbar disc herniation (LDH) before and after microdiscectomy. Methods: This was a prospective, observational study conducted on 59 cases of LDH planned for lumbar microdiscectomy, and healthy control group with 54 participants for analysis was performed prior to surgery and 15 days after surgery. The spatiotemporal gait parameters were measured using a “Win-Track” gait analysis platform system. All the participants walked barefoot for 10 times with their normal walking speed in the same day. The 3 flawless walking data were recorded and the arithmetic means were computed. The gait symmetry index was used to calculate the walking asymmetry. The pain intensity of the patients was recorded shortly before performing the analysis by a visual analogue scale. Results: In the postoperative assessment LDH patients had significantly shorter temporal parameters, longer spatial parameters, faster walking speed, and more cadence than the preoperative assessment (p < 0.05). There were improvements in the asymmetry values of the postoperative gait parameters compared to the preoperative values, but these differences were not significant (p > 0.05). In addition, there was a significant difference in all parameters in terms of gait asymmetry between the postoperative assessment and the healthy controls (p < 0.05). Conclusion: These results can guide the patient-specific evaluating and implementation of gait rehabilitation programs, and design protocols before or after surgery in the LDH patients.

Bias Atlases for Segmentation-Based PET Attenuation Correction Using PET-CT and MR

Jinsong Ouyang,Se Young Chun,Petibon, Yoann,Bonab, Ali A.,Alpert, Nathaniel,El Fakhri, Georges IEEE 2013 IEEE transactions on nuclear science Vol.60 No.5

<P>This study was to obtain voxel-wise PET accuracy and precision using tissue-segmentation for attenuation correction. We applied multiple thresholds to the CTs of 23 patients to classify tissues. For six of the 23 patients, MR images were also acquired. The MR fat/in-phase ratio images were used for fat segmentation. Segmented tissue classes were used to create attenuation maps, which were used for attenuation correction in PET reconstruction. PET bias images were then computed using the PET reconstructed with the original CT as the reference. We registered the CTs for all the patients and transformed the corresponding bias images accordingly. We then obtained the mean and standard deviation bias atlas using all the registered bias images. Our CT-based study shows that four-class segmentation (air, lungs, fat, other tissues), which is available on most PET-MR scanners, yields 15.1%, 4.1%, 6.6%, and 12.9% RMSE bias in lungs, fat, non-fat soft-tissues, and bones, respectively. An accurate fat identification is achievable using fat/in-phase MR images. Furthermore, we have found that three-class segmentation (air, lungs, other tissues) yields less than 5% standard deviation of bias within the heart, liver, and kidneys. This implies that three-class segmentation can be sufficient to achieve small variation of bias for imaging these three organs. Finally, we have found that inter- and intra-patient lung density variations contribute almost equally to the overall standard deviation of bias within the lungs.</P>

Consolidation deformation of Baghmisheh marls of Tabriz, Iran

Jalali-Milani, Shahrokh,Asghari-Kaljahi, Ebrahim,Barzegari, Ghodrat,Hajialilue-Bonab, Masoud Techno-Press 2017 Geomechanics & engineering Vol.12 No.4

Vast parts of the east of Tabriz city have been covered by Baghmisheh formation marls. These marls can be classified into three types based on their color as identified in yellow, green, and gray marls. Many high-rise buildings and other projects were founded and now is constructing on these marls. Baghmisheh formation marls are classified as stiff soil to very weak rock, therefore they undergo considerable consolidation settlement under foundation loads. This study presents the physical properties and consolidation behavior of these marls. According to the XRD tests, major clay minerals of marls are Illite, Kaolinite, Montmorillonite and Chloride. Uniaxial compressive strength are 100-250, 300-480 and 500-560 kPa for yellow, green and gray marls, respectively. Consolidation and creep behavior of Baghmisheh marls investigated by using of one dimensional consolidation apparatus under stress level up to 5 MPa. The results indicate that yellow marls have high compressibility, settlement and deformation modules. Green marls have an intermediate compressibility and settlement and while gray marls have low compressibility and settlement and from the foundation point of view have high stability. According to the creep test results, all types of marls have not been entered to progressive creep phase up to pressure 5 MPa.

Explaining the barriers and facilitators of ethnic and traditional food choices from the viewpoints of women

Arezoo Haghighian Roudsari,Abouali Vedadhir,Jamal Rahmani,Ali Milani Bonab 한국식품연구원 2019 Journal of Ethnic Foods Vol.6 No.-

Background and objectives: Women’s food choices and preferences are important as key decision-makers in household food handling, especially the selection of local and traditional foods that can potentially affect health and disease profile. Therefore, this study aimed to understand the barriers and facilitators of choosing local and traditional foods from the perspective of women living in Iran. Methods: This qualitative study was carried out using a semi-structured in-depth interview with 22 women aged 30–64 years old in Tehran (capital of Iran). The participants were recruited through purposive sampling with the maximum variation such as occupation, the district of residence, and education. Data collection and analysis were done simultaneously from the beginning of the study using the MAXQDA 10 software. Results and conclusions: The four main themes explored from the participants’ statements included: “cultural contexts,” “social barriers and motivations,” “convenience, accessibility, and skills,” and “religious considerations.” The lessons derived from family, experiences, beliefs, ethnicity patterns, influences from traditional medicine, and priorities in a lifetime, family preferences, routine complications, facilities and ingredients, cookery skills, and religious rules and occasions were extracted as sub-themes including the barriers and facilitators of local and traditional foods in women. Considering the diversity of local and traditional foods in Iranian culture, encouraging the varied consumption of these foods could contribute to the sustainability of diet in communities. Therefore, emphasizing the special role of Iranian women in the household, it is necessary to educate women in order to regenerate the local and traditional food patterns in our country.

Mechanical and Thermal Properties of Carbon/Basalt Intra-ply Hybrid Composites. I. Effect of Intra-ply Hybridization

Farzin Azimpour-Shishevan,Hamit Akbulut,M. A. Mohtadi-Bonab 한국섬유공학회 2020 Fibers and polymers Vol.21 No.11

The effects of intra-ply hybridization on mechanical and thermal properties of carbon/basalt fibers reinforcedepoxy composites were experimentally investigated. Combination of superior mechanical properties of carbon fiber, goodthermal stability and basalt fiber toughness is the main purpose of designing of these composites. Three types ofhomogeneous carbon fiber reinforced polymer (CFRP), basalt fiber reinforced polymer (BFRP) and intra-ply hybrid ofcarbon/basalt reinforced polymer (CBFRP) composites were fabricated by using vacuum assisted resin infusion molding(VARIM) method. All fabricated composite plates were cut according to ASTM standard. The effect of incorporation ofbasalt fiber with carbon fiber on mechanical properties, such as modulus of elasticity, tensile strength, flexural modulus,flexural strength and inter laminar shear strength (ILSS) were studied by bending, tensile and short beam shear (SBS)experiments. Measurement of thermal conductivity, dynamic mechanic analyze (DMA), thermogravimetric analyze (TGA)tests were also carried out for thermal characterization of fabricated homogeneous and hybrid composites. Furthermore,dynamic drop test (DDT) was used to evaluate hybridization effect on hydrophobicity of composites. The results indicatedthat the CBFP hybrid composites perform a moderate mechanical performance between homogeneous CFRP and BFRPcomposites. On the other hand, incorporation of basalt fiber in the structure of carbon fiber composite not only enhances thethermal stability of composites but also moderates the fabrication price by alternating cheaper basalt fiber with expensivecarbon fiber.

Assessing the impact of nanoclay on the permeability and geotechnical properties of fine-grained soils in landfill liners

Mahdi Nikbakht,Fariba Behrooz Sarand,Rouzbeh Dabiri,Masoud Hajialilue Bonab Techno-Press 2024 Advances in materials research Vol.13 No.1

Presented Article evaluates the effect of nanoclay on permeability, compressive strength, and plasticity behavior of fine-grained soil related to the Tabriz landfill site. In this regard, comprehensive experimental study was performed on taken soil samples (42 specimens) with aim of design high-performance liners for Tabriz landfill. The samples was mixed by 0% (control) 3%, 6% and 9% nanoclay and prepared in 1, 7, 14 and 28 days before testing stage. Index tests like particle-size, permeability, atterberg limits, and uniaxial compressive strength (UCS) was conducted on samples. The results show that studied soil is classified as CL in USCS classification and atterberg limits measured as LL is 37, PL is 20.67, and PI is 16.33 which increase into 75, 45, and 30. The assessment presented the LL was increased about 20.27% based on increasing in nanoclay from 0% to 9%. These variations for PL and PI were 21.77% and 18.37%, respectively. Also, the and soil's compressive strength is increase from 120 kPa to 188 kPa and permeability is estimated as 4.25×10^-6 m/s which reduced into the 6.34×10^-9 m/s with respect the naboclay content increases form 0% to 9%.