L.M. Quej-Ake, J. Marín-Cruz and A. Contreras
The purpose of this paper was to study the corrosion process of API X52, X60, X65, X70 and X80 steels exposed to two clay soils collected in two states of Mexico (Tabasco and…
Abstract
Purpose
The purpose of this paper was to study the corrosion process of API X52, X60, X65, X70 and X80 steels exposed to two clay soils collected in two states of Mexico (Tabasco and Campeche). To saturate the soils, 60 mL of deionized water was added to simulate the conditions for dry and wet season, due to in field, the climate change could modifies the physicochemical properties of the soils for each season of the year and this generate a variable environment, which affect the electrochemical responses on steel–soil interface.
Design/methodology/approach
The corrosion evaluation was carried out simulating the conditions of deteriorated coating (bare steel); this includes steel surface exposed to clay soil affected by seasonal fluctuations in a tropical zone. These soils were characterized, without any further treatment as were found in the field (dry season). Moreover, some samples were taken and prepared to analyze in laboratory. For each soil sample, 60 mL of deionized water was added to simulate the rainy season (saturated soils). Electrochemical evaluations were carried out after 3 h of exposure time at room temperature. Because soil is a system with high resistivity and impedance, it is necessary to carry out IR-drop compensation using two platinum rods that were used as an auxiliary electrode. In addition, the IR-drop correction obtained from the experimental potentiodynamic curves was investigated.
Findings
In clay from Campeche (Clay-C), the more susceptible steel to corrosion was X65, whereas in clay from Tabasco (Clay-T), the more susceptible steel to corrosion was X80 steel. Electrochemical results show that despite higher-degree steels providing higher strength and hardness, the order of corrosion susceptibility is random, which can be attributed to different microstructures in the steels. The complexity of the corrosion process on five steels was evident when steel samples were exposed to different soils. The higher corrosion rate was obtained in X65 steel (0.5 mm/year).
Practical implications
The paper clearly identifies any implication for the research.
Originality/value
The electrochemical responses of different steels exposed in two types of clay soil explained the corrosion complexity that can be attributed to changes in physicochemical properties of the soils, which are because of changes in seasons (dry and rainy) and the microstructure of each steel related to the process of fabrication. Suggesting that the increase in mechanical properties such as hardness and resistance of the pipeline steels could not be associated with its corrosion resistance, the corrosion susceptibility is more dependent on the microstructure of the steels.
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L.M. Quej-Ake and A. Contreras
The purpose of this work is to study the corrosion rate of X52 pipeline steel exposed to three types of soils collected in Campeche State in México. The electrochemical evaluation…
Abstract
Purpose
The purpose of this work is to study the corrosion rate of X52 pipeline steel exposed to three types of soils collected in Campeche State in México. The electrochemical evaluation for X52 steel exposed to soils ranging from saturated soil until dry conditions was carried out for a period of 21 days. Owing to its versatility to study the steel corrosion process exposed to different types of soils, electrochemical impedance spectroscopy (EIS), potentiodynamic polarization and cyclic voltammetry tests were performed. Additionally, optical and electronic microscopy observations of the steel surface were carried out.
Design/methodology/approach
Electrochemical cell arrangement was described elsewhere (Quej-Ake et al., 2014). Owing to soil being an electrolytic system with high resistivity and impedance, all electrodes were placed as close as possible, and iR-drop compensation was taken into account using two rods of graphite as an auxiliary electrode. In addition, the conductivity of the soil (Rs) obtained from EIS was used to correct the potential of the working electrode according to iR-drop, and an analysis of ohmic drop from the polarization curves was carried out.
Findings
Saturated conditions of the three soils were initially considered as the most corrosive conditions for X52 steel surface. Finally, 21 days of immersion time was taken into account as the more drastic condition. So, according to results, X52 steel exposed to beach sand was more susceptible to the corrosion process (0.092 mm/year). iR corrected was negligible at low over-potentials region in saturated soils, which is inside the linear region of Tafel or the activation region. In addition, high cathodic peak potential value obtained from cyclic voltammetry for X52 steel exposed to saturated soil may be attributed to hydrogen evolution reaction and neutral pH.
Research limitations/implications
The paper has implications for research. It bridges the gap between theory and practice.
Originality/value
Cyclic voltammetry is a really important tool for the electrochemical analysis of the pipeline steel surface exposed to saturated soils, but is not adequate for analysis of steel exposed to dried soils. In addition, the physicochemical results show that fissures, voids and extra-oxygen presence could also affect the electrochemical responses obtained for X52 steel exposed to soils.
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Kamal T. Hindy and Ashraf R. Baghdady
Deals with a study of the mineralogical and organic components of the monthly dust‐fall deposited over Al Ain city, some 150km east of Abu Dhabi and 130km south‐east of Dubai. The…
Abstract
Deals with a study of the mineralogical and organic components of the monthly dust‐fall deposited over Al Ain city, some 150km east of Abu Dhabi and 130km south‐east of Dubai. The identification of the mineralogical and organic composition was carried out by means of infra‐red spectroscopy. This study reveals that the principal constituents of dustfall, over the studied city are calcite, gypsum, kaolinite, quartz, hematite, alkanes and phosphines. The sources of these constituents are attributed to local controls, both natural and man‐induced
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The surface temperature of the sub-roof beneath the ventilation layer and the tiles is one of the most important factors for the hygrothermal performance of pitched roofs. The air…
Abstract
Purpose
The surface temperature of the sub-roof beneath the ventilation layer and the tiles is one of the most important factors for the hygrothermal performance of pitched roofs. The air layer between tiles and sub-roof and the air exchange with the outdoor air influence the heat transfer and therefore affect the moisture level inside the roof construction. The paper aims to discuss these issues.
Design/methodology/approach
This paper provides the results of a research project performed at Fraunhofer-Institute for Building Physics, based on field test results. The investigations analyze the thermal behavior of different vented and ventilated roof constructions.
Findings
It was found that for a detailed model with roof cladding and ventilated air layer normally too many parameters are unknown. For that reason a simplified approach was set up, especially to consider the radiation exchange between the tiles and the underlay as well as the effects of the ventilation.
Originality/value
Now, effective surface transfer parameters can substitute both cladding and air layer in the simulation, while the approach still provides a high accordance with the measured values. The paper provides characteristic values for different roofing situations to simulate ventilated roofs by means of hygrothermal simulation in a simplified way.
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Retrospective conversion is a costly endeavor, especially when the quality of description utilized during the mark‐up process is insufficient according to data content standards…
Abstract
Retrospective conversion is a costly endeavor, especially when the quality of description utilized during the mark‐up process is insufficient according to data content standards. When retrospective conversion is implemented in a cooperative project, the problems are compounded. Administrators and encoders alike are forced to reckon with legacy data formats and descriptive styles that do not match those utilized in their own archival practices. Often, more time and financial expenditures must be placed on administrative duties in order to deal with the lack of standardization. Efforts to mitigate the high cost of cooperative projects are discussed.
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Linu Babu, S. Vishnu Mohan, Mahesh Mohan and A.P. Pradeepkumar
This paper aims to examine the geochemical change experienced by laterites in Kerala, India, subjected to tropical monsoonal climate. These sediments are underlain by hard rock…
Abstract
Purpose
This paper aims to examine the geochemical change experienced by laterites in Kerala, India, subjected to tropical monsoonal climate. These sediments are underlain by hard rock. The source rock characteristics have a major stake on the ultimate composition of sediments, as also the climatic conditions which an area experience.
Design/methodology/approach
Core samples have been obtained from several locations in a lateritic plateau. The upper portions of the borehole cores are composed of the lateritic hard cap, followed by lateritic soils. The soil samples were subjected to sediment texture analysis and XRF analysis (Bruker S4 Pioneer Sequential Wavelength-Dispersive XRF) for the determination of major elements ((in oxide form).
Findings
Major element geochemistry has revealed the following order of relative proportions of elements (in oxide form) SiO2 > Al2O3 > Fe2O3 > TiO2 >> Na2O > P2O5 > CaO > K2O > MgO > MnO. Even though the concentrations of SiO2, Al2O3 and Fe2O3 contribute 90% of major element chemistry, there is no significant correlation found for these elements within themselves or with others.
Research limitations/implications
Microscale movement of elements could not be characterised in this study. This requires access to an electron probe micro analyzer.
Practical implications
The practical implication of tropical weathering is that enhanced chemical leaching leads to movement of most elements out of the system, except for Al, leading to the possible formation of bauxite, or aluminous laterite.
Social implications
The weathered products in this study provide livelihood sustenance for many of the local households, through manual production of laterite bricks, which are used in construction.
Originality/value
The indices of the intensity of chemical alteration/weathering like chemical index of alteration (CIA), chemical index of weathering (CIW) and weathering index of parker (WIP) reveal that the sediments indicate intense weathering of the source area prior to being deposited in the present location. This indicates enhanced monsoonal activity in the provenance areas, than that obtained today.
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Sanjay Mohapatra, Amit Nayak, Ankita Bhangadiya, Ipshit Bagchi, Pradeep Kumar Sharma and Sukanya Behera
The case concerns strategy.
Abstract
Subject area
The case concerns strategy.
Study level/applicability
This study is applicable to information system, development sector and application of technology in development sector.
Case overview
Krutika Terracotta Unit is a small unit located in Bhubaneswar, Odisha (India), owned by Mr Tarun Tapan Sahoo. The organization product portfolio varies from decorative statues, pots and vessel to customized products demanded by customers. Organization is also involved in training and renting the products for traditional fairs, marriages and religious ceremony in Bhubaneswar along with order sales. The case attempts to get a close picture of the industry. The exercise of developing the vision, mission, and goals for the organization was carried out and an attempt was made to align the information system with the business objectives even though the organization does not have a very structured organogram. Using BIS will surely reduce manual work and will give qualitative output. There will be lesser hassles in management. The defined and integrated approach will also help in taking strategic decisions well. The objective is to develop and apply well-structured BIS which can be integrated with the existing system so as to develop the terracotta organization in terms of reachability and profit-making with better decision-making capacity.
Expected learning outcomes
To learn about the business model of a handicraft marketing organization; to learn about the processes involved in traditional art form of Terracotta; to go through the exercise of creating vision, mission, goals of the organization through mutual discussion and expectation of owner; to determine how BIS helps in achieving higher productivity in Krutika Terracotta Unit; and to get an idea about how NPV calculation and social ROI should be measured for finding feasibility of technology investment.
Supplementary materials
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Victoria Gurieva, Anastasia Ilyina, Sergey Klyuev, Magomed Saidumov, Tolya Khezhev, Igor Nedoseko, Roman Fediuk, Vitaly Shamanov and Batyr Yazyev
The study suggests that the high concentration of mining and metallurgical enterprises on the territory of the Russian Ural region determines the need to consider industrial…
Abstract
Purpose
The study suggests that the high concentration of mining and metallurgical enterprises on the territory of the Russian Ural region determines the need to consider industrial waste, including nickel slag, as a possible raw material for the production of ceramic bricks. The article describes the properties of clays and nickel slag obtained at metallurgical enterprises in the Orenburg region and the features of their use as components in the composition of ceramic bricks.
Design/methodology/approach
To achieve this purpose, such tasks as determining the technological parameters of production, conducting the X-ray phase and microstructural analysis of the obtained samples were solved.
Findings
Compositions of ceramic mass using clay from the Khalilovsky deposit (Orenburg region) with the addition of nickel slag (20 and 40% by weight) have been developed, and their physical and mechanical properties (compressive strength, bending strength, water absorption and density) have been determined. With the help of modern research methods involving high-tech equipment, the microstructure is considered and the phase composition of the finished samples is determined. As a result of the conducted research, it was found that the composition of the selected clay and nickel slag in the obtained rational composition ensures the production of ceramic bricks of grades M175 and M200.
Originality/value
This is the first study on the use of nickel slag for the production of ceramic bricks. The results relate primarily to Russian feedstocks, but a methodology is presented that can be applied to other countries as well as to other silica-containing feedstocks.
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You Wang, Tingting Ma and Jialin Ren
The purpose of this paper is to explore the variation law between the clay microstructure and macro external force by using soil scanning electron microscope (SEM) images.
Abstract
Purpose
The purpose of this paper is to explore the variation law between the clay microstructure and macro external force by using soil scanning electron microscope (SEM) images.
Design/methodology/approach
First, SEM images of clay were pre-processed by MATLAB, and quantitative statistical parameters such as directional probability entropy, fractal dimension and shape factor are extracted. Second, the distribution force model was proposed, considering that the microscopic parameters of soil particles were independent of each other, and the distribution coefficient was determined according to the analytic hierarchy process (AHP). Then, the fitted formula of quantitative statistical parameters based on the distribution force model was obtained by taking the macroscopic distribution force as independent variable and the microscopic parameters of soil particles as dependent variable. Finally, the correctness of corresponding fitting formula was verified.
Findings
The results showed that the change of external consolidation pressure has great influence on the directional probability entropy and fractal dimension, while the shape factor reflecting the regular degree of soil particle shape is less sensitive to the consolidation pressure. The fitting formula has high accuracy, and mostly the R value can reach more than 0.9. All the data have passed the test, which proves that the distribution force model proposed in this paper is rational.
Originality/value
The model can be used to connect the macroscopic stress of soil with the micro-structure deformation of soil particles through mathematical formula, which can provide reference for engineering practice.
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John L. Daniels, Raghuram Cherukuri, Helene A. Hilger, James D. Oliver and Shi Bin
The purpose of this paper is to evaluate the influence of a mixture of nutrient solution, bacteria and biofilm on the consolidation, unconfined compression and desiccation…
Abstract
Purpose
The purpose of this paper is to evaluate the influence of a mixture of nutrient solution, bacteria and biofilm on the consolidation, unconfined compression and desiccation characteristics of two soils that could be used in waste containment applications.
Design/methodology/approach
Experimental work was conducted to investigate the influence of biofilm on the desiccation, strength and consolidation characteristics of two barrier soils. The soils were evaluated with water alone and with a biofilm solution composed of nutrients, bacteria and exopolymeric substances (EPS). These solutions were mixed with a locally available clay (“red bull tallow” (RBT)) as well as a mix of 65 percent sand and 35 percent bentonite (65‐35 Mix).
Findings
Reductions in strength and increases in ductility are observed with biofilm amendment for two soil types. The shear strength was reduced from 413 to 313 kPa and from 198 to 179 kPa for RBT and 65‐35 Mix, respectively. Desiccation tests reveal an increase in moisture retention for early time increments in amended specimens, while both increases and decreases are noted after extended drying. Increases in the rate of consolidation and modest decreases in the compression and swell index were observed. In particular, the consolidation coefficient was increased from 0.036 to 0.064 cm2/min and from 0.060 to 0.093 cm2/min for RBT and 65‐35 Mix, respectively.
Practical implications
These results are useful in establishing the broader impacts of using biofilm as an additive to increase the performance (e.g. reduce hydraulic conductivity and increase resistance to crack formation) of barrier materials in waste containment applications. Moreover, the data provide insight into the geotechnical implications of biofilm‐producing methanotrophic activity that occurs naturally in the covers of municipal solid waste landfills.
Originality/value
Very little research has been published on the influence of biofilm on the behavior of barrier materials in general, and on geotechnical properties in particular. This paper is unique in making the connection between methanotrophic activity, soil modification and barrier material performance.