Search results for: orthotropic steel bridge deck
Commenced in January 2007
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Edition: International
Paper Count: 2521

Search results for: orthotropic steel bridge deck

601 Numerical Simulation of Fluid-Structure Interaction on Wedge Slamming Impact by Using Particle Method

Authors: Sung-Chul Hwang, Di Ren, Sang-Moon Yoon, Jong-Chun Park, Abbas Khayyer, Hitoshi Gotoh

Abstract:

The slamming impact problem has a very important engineering background. For seaplane landing, recycling for the satellite re-entry capsule, and the impact load of the bow in the adverse sea conditions, the slamming problem always plays the important role. Due to its strong nonlinear effect, however, it seems to be not easy to obtain the accurate simulation results. Combined with the strong interaction between the fluid field and the elastic structure, the difficulty for the simulation leads to a new level for challenging. This paper presents a fully Lagrangian coupled solver for simulations of fluid-structure interactions, which is based on the Moving Particle Semi-implicit (MPS) method to solve the governing equations corresponding to incompressible flows as well as elastic structures. The developed solver is verified by reproducing the high velocity impact loads of deformable thin wedges with two different materials such as aluminum and steel on water entry. The present simulation results are compared with analytical solution derived using the hydrodynamic Wagner model and linear theory by Wan.

Keywords: fluid-structure interaction, moving particle semi-implicit (MPS) method, elastic structure, incompressible flow, wedge slamming impact

Procedia PDF Downloads 585
600 Reduction Behavior of Some Low-Grade Iron Ores for Application in Blast Furnace

Authors: Heba Al-Kelesh

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Day after day, high-grade iron ores are consumed. Because of the strong global demand for iron and steel, it has necessitated the utilization of various low-grade iron ores, which are not suitable for direct exploitation in the iron industry. The low-grade ores cannot be dressed using traditional mineral processing methods because of complicated mineral compositions. The present work is aimed to investigate the reducibility of some Egyptian iron ores and concentrates by conditions emulate different blast furnace areas. Representative specimens are collected from El-Gedida–Baharia oasis, Eastern South Aswan, and Eastern desert-wadi Kareem (EDC). Some mineralogical and morphological characterizations are executed. The reactivity arrangement of green samples is Baharia>Aswan>EDC. The presence of magnetite decreased reactivity of EDC. The reducibility of the Aswan sample is lower than Baharia due to the presence of agglomerated metallic grain surrounded by semi-melted phases. Specimens are annealed at 1000ᵒC for 3 hours. After firing, the reducibility of Aswan becomes the lowest due to the formation of fayalite and calcium phosphate phases. The relative attitude for green and fired samples reduced at different conditions are studied. For thermal and top areas, the reactivity of fired samples is greater than green ones, which were confirmed by morphological examinations.

Keywords: reducibility, low grade, iron industry, blast furnace

Procedia PDF Downloads 113
599 Evaluation of Mechanical Properties of Welds Fabricated at a Close Proximity on Offshore Structures

Authors: T. Nakkeran, C. Dhamodharan, Win Myint Soe , Ramasamy Deverajan, M. Ganesh Babu

Abstract:

This manuscript presents the results of an experimental investigation performed to study the material and mechanical properties of two weld joints fabricated within close proximity. The experiment was designed using welded S355 D Z35 with distances between two parallel adjacent weld toes at 8 mm. These distances were less than the distance that has normally been recommended in standards, codes, and specifications. The main idea of the analysis is to determine any significant effects when welding the joints with the close proximity of 8mm using the SAW welding process of the one joint with high heat put and one joint welded with the FCAW welding process and evaluating the destructing and nondestructive testing between the welded joints. Further, we have evaluated the joints with Mechanical Testing for evaluating by performing Tensile test, bend testing, Macrostructure, Microstructure, Hardness test, and Impact testing. After evaluating the final outcome of the result, no significant changes were observed for welding the close proximity of weld of 8mm distance between the joints as compared to the specification minimum distance between the weldments of any design should be 50mm.

Keywords: S355 carbon steel, weld proximity, SAW process, FCAW process, heat input, bend test, tensile test, hardness test, impact test, macro and microscopic examinations

Procedia PDF Downloads 88
598 Metallic Coating for Carbon Fiber Reinforced Polymer Matrix Composite Substrate

Authors: Amine Rezzoug, Said Abdi, Nadjet Bouhelal, Ismail Daoud

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This paper investigates the application of metallic coatings on high fiber volume fraction carbon/epoxy polymer matrix composites. For the grip of the metallic layer, a method of modifying the surface of the composite by introducing a mixture of copper and steel powder (filler powders) which can reduce the impact of thermal spray particles. The powder was introduced to the surface at the time of the forming. Arc spray was used to project the zinc coating layer. The substrate was grit blasted to avoid poor adherence. The porosity, microstructure, and morphology of layers are characterized by optical microscopy, SEM and image analysis. The samples were studied also in terms of hardness and erosion resistance. This investigation did not reveal any visible evidence damage to the substrates. The hardness of zinc layer was about 25.94 MPa and the porosity was around (∼6.70%). The erosion test showed that the zinc coating improves the resistance to erosion. Based on the results obtained, we can conclude that thermal spraying allows the production of protective coating on PMC. Zinc coating has been identified as a compatible material with the substrate. The filler powders layer protects the substrate from the impact of hot particles and allows avoiding the rupture of brittle carbon fibers.

Keywords: arc spray, coating, composite, erosion

Procedia PDF Downloads 439
597 "Empowering Minds and Unleashing Curiosity: DIY Biotechnology for High School Students in the Age of Distance Learning"

Authors: Victor Hugo Sanchez Rodriguez

Abstract:

Amidst the challenges posed by pandemic-induced lockdowns, traditional educational models have been disrupted. To bridge the distance learning gap, our project introduces an innovative initiative focused on teaching high school students basic biotechnology techniques. We aim to empower young minds and foster curiosity by encouraging students to create their own DIY biotechnology laboratories using easily accessible materials found at home. This abstract outlines the key aspects of our project, highlighting its importance, methodology, and evaluation approach.In response to the pandemic's limitations, our project targets the delivery of biotechnology education at a distance. By engaging students in hands-on experiments, we seek to provide an enriching learning experience despite the constraints of remote learning. The DIY approach allows students to explore scientific concepts in a practical and enjoyable manner, nurturing their interest in biotechnology and molecular biology. Originally designed to assess professional-level research programs, we have adapted the URSSA to suit the context of biotechnology and molecular biology synthesis for high school students. By applying this tool before and after the experimental sessions, we aim to gauge the program's impact on students' learning experiences and skill development. Our project's significance lies not only in its novel approach to teaching biotechnology but also in its adaptability to the current global crisis. By providing students with a stimulating and interactive learning environment, we hope to inspire educators and institutions to embrace creative solutions during challenging times. Moreover, the insights gained from our evaluation will inform future efforts to enhance distance learning programs and promote accessible science education.

Keywords: DIY biotechnology, high school students, distance learning, pandemic education, undergraduate research student self-assessment (URSSA)

Procedia PDF Downloads 59
596 Flexural Fatigue Performance of Self-Compacting Fibre Reinforced Concrete

Authors: Surinder Pal Singh, Sanjay Goel

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The paper presents results of an investigation conducted to study the flexural fatigue characteristics of Self Compacting Concrete (SCC) and Self Compacting Fibre Reinforced Concrete (SCFRC). In total 360 flexural fatigue tests and 270 static flexural strength tests were conducted on SCC and SCFRC specimens to obtain the fatigue test data. The variability in the distribution of fatigue life of SCC and SCFRC have been analyzed and compared with that of NVC and NVFRC containing steel fibres of comparable size and shape. The experimental coefficients of fatigue equations have been estimated to represent relationship between stress level (S) and fatigue life (N) for SCC and SCFRC containing different fibre volume fractions. The probability of failure (Pf) has been incorporated in S-N relationships to obtain families of S-N-Pf relationships. A good agreement between the predicted curves and those obtained from the test data has been observed. The fatigue performance of SCC and SCFRC has been evaluated in terms of two-million cycles fatigue strength/endurance limit. The theoretic fatigue lives were also estimated using single-log fatigue equation for 10% probability of failure to estimate the enhanced extent of theoretic fatigue lives of SCFRC with reference to SCC and NVC. The reduction in variability in the fatigue life, increased endurance limit and increased theoretiac fatigue lives demonstrates an overall better fatigue performance for SCC and SCFRC.

Keywords: fatigue life, fibre, probability of failure, self-compacting concrete

Procedia PDF Downloads 343
595 Analysis of Hard Turning Process of AISI D3-Thermal Aspects

Authors: B. Varaprasad, C. Srinivasa Rao

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In the manufacturing sector, hard turning has emerged as vital machining process for cutting hardened steels. Besides many advantages of hard turning operation, one has to implement to achieve close tolerances in terms of surface finish, high product quality, reduced machining time, low operating cost and environmentally friendly characteristics. In the present study, three-dimensional CAE (Computer Aided Engineering) based simulation of  hard turning by using commercial software DEFORM 3D has been compared to experimental results of  stresses, temperatures and tool forces in machining of AISI D3 steel using mixed Ceramic inserts (CC6050). In the present analysis, orthogonal cutting models are proposed, considering several processing parameters such as cutting speed, feed, and depth of cut. An exhaustive friction modeling at the tool-work interfaces is carried out. Work material flow around the cutting edge is carefully modeled with adaptive re-meshing simulation capability. In process simulations, feed rate and cutting speed are constant (i.e.,. 0.075 mm/rev and 155 m/min), and analysis is focused on stresses, forces, and temperatures during machining. Close agreement is observed between CAE simulation and experimental values.

Keywords: hard turning, computer aided engineering, computational machining, finite element method

Procedia PDF Downloads 443
594 Signal Processing of Barkhausen Noise Signal for Assessment of Increasing Down Feed in Surface Ground Components with Poor Micro-Magnetic Response

Authors: Tanmaya Kumar Dash, Tarun Karamshetty, Soumitra Paul

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The Barkhausen Noise Analysis (BNA) technique has been utilized to assess surface integrity of steels. But the BNA technique is not very successful in evaluating surface integrity of ground steels that exhibit poor micro-magnetic response. A new approach has been proposed for the processing of BN signal with Fast Fourier transforms while Wavelet transforms has been used to remove noise from the BN signal, with judicious choice of the ‘threshold’ value, when the micro-magnetic response of the work material is poor. In the present study, the effect of down feed induced upon conventional plunge surface grinding of hardened bearing steel has been investigated along with an ultrasonically cleaned, wet polished and a sample ground with spark out technique for benchmarking. Moreover, the FFT analysis has been established, at different sets of applied voltages and applied frequency and the pattern of the BN signal in the frequency domain is analyzed. The study also depicts the wavelet transforms technique with different levels of decomposition and different mother wavelets, which has been used to reduce the noise value in BN signal of materials with poor micro-magnetic response, in order to standardize the procedure for all BN signals depending on the frequency of the applied voltage.

Keywords: barkhausen noise analysis, grinding, magnetic properties, signal processing, micro-magnetic response

Procedia PDF Downloads 657
593 Comparison between Pushover Analysis Techniques and Validation of the Simplified Modal Pushover Analysis

Authors: N. F. Hanna, A. M. Haridy

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One of the main drawbacks of the Modal Pushover Analysis (MPA) is the need to perform nonlinear time-history analysis, which complicates the analysis method and time. A simplified version of the MPA has been proposed based on the concept of the inelastic deformation ratio. Furthermore, the effect of the higher modes of vibration is considered by assuming linearly-elastic responses, which enables the use of standard elastic response spectrum analysis. In this thesis, the simplified MPA (SMPA) method is applied to determine the target global drift and the inter-story drifts of steel frame building. The effect of the higher vibration modes is considered within the framework of the SMPA. A comprehensive survey about the inelastic deformation ratio is presented. After that, a suitable expression from literature is selected for the inelastic deformation ratio and then implemented in the SMPA. The estimated seismic demands using the SMPA, such as target drift, base shear, and the inter-story drifts, are compared with the seismic responses determined by applying the standard MPA. The accuracy of the estimated seismic demands is validated by comparing with the results obtained by the nonlinear time-history analysis using real earthquake records.

Keywords: modal analysis, pushover analysis, seismic performance, target displacement

Procedia PDF Downloads 353
592 Corrosion Resistance Performance of Epoxy/Polyamidoamine Coating Due to Incorporation of Nano Aluminium Powder

Authors: Asiful Hossain Seikh, Mohammad Asif Alam, Ubair Abdus Samad, Jabair A. Mohammed, S. M. Al-Zahrani, El-Sayed M. Sherif

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In this current investigation, aliphatic amine-cured diglycidyl ether of bisphenol-A (DGEBA) based epoxy coating was mixed with certain weight % hardener polyaminoamide (1:2) and was coated on carbon steel panels with and without 1% nano crystalline Al powder. The corrosion behavior of the coated samples were investigated by exposing them in the salt spray chamber, for 500 hours. According to ASTM-B-117, the bath was kept at 35 °C and 5% NaCl containing mist was sprayed at 1.3 bars pressure. Composition of coatings was confirmed using Fourier-transform infrared spectroscopy (FTIR). Electrochemical characterization of the coated samples was also performed using potentiodynamic polarization technique and electrochemical impedance spectroscopy (EIS) technique. All the experiments were done in 3.5% NaCl solution. The nano Al coated sample shows good corrosion resistance property compared to bare Al sample. In fact after salt spray exposure no pitting or local damage was observed for nano coated sample and the coating gloss was negligibly affected. The surface morphology of coated and corroded samples was studied using scanning electron microscopy (SEM).

Keywords: epoxy, nano aluminium, potentiodynamic polarization, salt spray, electrochemical impedence spectroscopy

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591 Using Geopolymer Technology on Stabilization and Reutilization the Expansion Behavior Slag

Authors: W. H. Lee, T. W. Cheng, K. Y. Lin, S. W. Huang, Y. C. Ding

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Basic Oxygen Furnace (BOF) Slag and electric arc furnace (EAF) slag is the by-product of iron making and steel making. Each of slag with produced over 100 million tons annually in Taiwan. The type of slag has great engineering properties, such as, high hardness and density, high compressive strength, low abrasion ratio, and can replace natural aggregate for building materials. However, no matter BOF or EAF slag, both have the expansion problem, due to it contains free lime. The purpose of this study was to stabilize the BOF and EAF slag by using geopolymer technology, hoping can prevent and solve the expansion problem. The experimental results showed that using geopolymer technology can successfully solve and prevent the expansion problem. Their main properties are analyzed with regard to their use as building materials. Autoclave is used to study the volume stability of these specimens. Finally, the compressive strength of geopolymer mortar with BOF/FAF slag can be reached over 21MPa after curing for 28 days. After autoclave testing, the volume expansion does not exceed 0.2%. Even after the autoclave test, the compressive strength can be grown to over 35MPa. In this study have success using these results on ready-mixed concrete plant, and have the same experimental results as laboratory scale. These results gave encouragement that the stabilized and reutilized BOF/EAF slag could be replaced as a feasible natural fine aggregate by using geopolymer technology.

Keywords: BOF slag, EAF slag, autoclave test, geopolymer

Procedia PDF Downloads 124
590 Comparison of Double Unit Tunnel Form Building before and after Repair and Retrofit under in-Plane Cyclic Loading

Authors: S. A. Anuar, N. H. Hamid, M. H. Hashim, S. M. D. Salleh

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This paper present the experimental work on the seismic performance of double unit tunnel form building (TFB) subjected to in-plane lateral cyclic loading. A one third scale of 3-storey double unit of TFB is tested at ±0.01%, ±0.1%, ±0.25%, ±0.5%, ±0.75% and ±1.0% drifts until the structure achieves its strength degradation. After that, the TFB is repaired and retrofitted using additional shear wall, steel angle and CFRP sheet. A similar testing approach is applied to the specimen after repair and retrofit. The crack patterns, lateral strength, stiffness, ductility and equivalent viscous damping (EVD) were analyzed and compared before and after repair and retrofit. The result indicates that the lateral strength increases by 22 in pushing direction and 27% in pulling direction. Moreover, the stiffness and ductility obtained before and after retrofit increase tremendously by 87.87% and 39.66%, respectively. Meanwhile, the energy absorption measured by equivalent viscous damping obtained after retrofit increase by 12.34% in pulling direction. It can be concluded that the proposed retrofit method is capable to increase the lateral strength capacity, stiffness and energy absorption of double unit TFB.

Keywords: tunnel form building, in-plane lateral cyclic loading, crack pattern, lateral strength, stiffness, ductility, equivalent viscous damping, repair and retrofit

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589 Homogeneous Anti-Corrosion Coating of Spontaneously Dissolved Defect-Free Graphene

Authors: M. K. Bin Subhan, P. Cullen, C. Howard

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A recent study by the World Corrosion Organization estimated that corrosion related damage causes $2.5tr worth of damage every year. As such, a low cost easily scalable solution is required to the corrosion problem which is economically viable. Graphene is an ideal anti-corrosion barrier layer material due to its excellent barrier properties and chemical stability, which makes it impermeable to all molecules. However, attempts to employ graphene as a barrier layer has been hampered by the fact that defect sites in graphene accelerate corrosion due to the inert nature of graphene which promotes galvanic corrosion at the expense of the metal. The recent discovery of spontaneous dissolution of charged graphite intercalation compounds in aprotic solvents enables defect free graphene platelets to be employed for anti-corrosion applications. These ‘inks’ of defect-free charged graphene platelets in solution can be coated onto a metallic surfaces via electroplating to form a homogeneous barrier layer. In this paper, initial data showing homogeneous coatings of graphene barrier layers on steel coupons via electroplating will be presented. This easily scalable technique also provides a controllable method for applying different barrier thicknesses from ultra thin layers to thick opaque coatings making it useful for a wide range of applications.

Keywords: anti-corrosion, defect-free, electroplating, graphene

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588 An Exploration of Architecture Design Methods in Urban Fringe Belt Based on Typo-Morphological Research- A Case of Expansion Project of the Second Middle School in Xuancheng, China

Authors: Dong Yinan, Zhou Zijie

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Urban fringe belt is an important part of urban morphology research. Different from the relatively fixed central district of city, the position of fringe belt is changing. In the process of urban expansion, the original fringe belt is likely to be merged by the new-built city, even become new city public center. During the change, we are facing the dialectic between restoring the organicity of old urban form and creating new urban image. There are lots of relevant research in urban scale, but when we focus on building scale, rare design method can be proposed, thus some new individual building cannot match the overall urban planning intent. The expansion project of the second middle school in Xuancheng is facing this situation. The existing campus is located in the south fringe belt of Xuancheng, Anhui province, China, adjacent to farmland and ponds. While based on the Xucheng urban planning, the farmland and ponds will be transformed into a big lake, around which new public center will be built; the expansion of the school becomes an important part of the boundary of the new public center. Therefore, the expansion project faces challenges from both urban and building scale. In urban scale, we analyze and summarize the fringe belt characters through the reading of existing and future urban organism, in order to determine the form of the expansion project. Meanwhile, in building scale, we study on different types of school buildings and select appropriate type which can satisfy to both urban form and school function. This research attempts to investigate design methods based on an under construction project in Xuancheng, a historic city in southeast China. It also aims to bridge the gap from urban design to individual building design through the typo-morphological research.

Keywords: design methods, urban fringe belt, typo-morphological research, middle school

Procedia PDF Downloads 487
587 Bridge Healthcare Access Gap with Artifical Intelligence

Authors: Moshmi Sangavarapu

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The US healthcare industry has undergone tremendous digital transformation in recent years, but critical care access to lower-income ethnicities is still in its nascency. This population has historically showcased substantial hesitation to seek any medical assistance. While the lack of sufficient financial resources plays a critical role, the existing cultural and knowledge barriers also contribute significantly to widening the access gap. It is imperative to break these barriers to ensure timely access to therapeutic procedures that can save important lives! Based on ongoing research, healthcare access barriers can be best addressed by tapping the untapped potential of caregiver communities first. They play a critical role in patients’ diagnoses, building healthcare knowledge and instilling confidence in required therapeutic procedures. Recent technological advancements have opened many avenues by developing smart ways of reaching the large caregiver community. A digitized go-to-market strategy featuring connected media coupled with smart IoT devices and geo-location targeting can be collectively leveraged to reach this key audience group. AI/ML algorithms can be thoroughly trained to identify relevant data signals from users' location and browsing behavior and determine useful marketing touchpoints. The web behavior can be further assimilated with natural language processing to identify contextually relevant interest topics and decipher potential caregivers on digital avenues to serve that brand message. In conclusion, grasping the true health access journey of any lower-income ethnic group is important to design beneficial touchpoints that can alleviate patients’ concerns and allow them to break their own access barriers and opt for timely and quality healthcare.

Keywords: healthcare access, market access, diversity barriers, patient journey

Procedia PDF Downloads 38
586 Investigation of the Role of Friction in Reducing Pedestrian Injuries in Accidents at Intersections

Authors: Seyed Abbas Tabatabaei, Afshin Ghanbarzadeh, Mehdi Abidizadeh

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Nowadays the subject of road traffic accidents and the high social and economic costs due to them is the most fundamental problem that experts and providers of transport and traffic brought to a challenge. One of the most effective measures is to enhance the skid resistance of road surface. This research aims to study the intersection of one case in Ahwaz and the effect of increasing the skid resistance in reducing pedestrian injuries in accidents at intersections. In this research the device was developed to measure the coefficient of friction and tried the rules and practices of it have a high similarity with the Locked Wheel Trailer. This device includes a steel frame, wheels, hydration systems, and force gauge. The output of the device is that the force gauge registers. By investigate this data and applying the relationships relative surface coefficient of friction is obtained. Friction coefficient data for the current state and the state of the new pavement are obtained and plotted on the graphs based on the graphs we can compare the two situations and speed at the moment of collision between the two modes are compared. The results show that increasing the coefficient of friction to what extent can be effective on the severity and number of accidents.

Keywords: intersection, coefficient of friction, skid resistance, locked wheels, accident, pedestrian

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585 The Effect of Feedstock Powder Treatment / Processing on the Microstructure, Quality, and Performance of Thermally Sprayed Titanium Based Composite Coating

Authors: Asma Salman, Brian Gabbitas, Peng Cao, Deliang Zhang

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The performance of a coating is strongly dependent upon its microstructure, which in turn is dependent on the characteristics of the feedstock powder. This study involves the evaluation and performance of a titanium-based composite coating produced by the HVOF (high-velocity oxygen fuel) spraying method. The feedstock for making the composite coating was produced using high energy mechanical milling of TiO2 and Al powders followed by a combustion reaction. The characteristics of the feedstock powder were improved by treating it with an organic binder. Two types of coatings were produced using treated and untreated feedstock powders. The microstructures and characteristics of both types of coatings were studied, and their thermal shock resistance was accessed by dipping into molten aluminum. The results of this study showed that feedstock treatment did not have a significant effect on the microstructure of the coatings. However, it did affect the uniformity, thickness and surface roughness of the coating on the steel substrate. A coating produced by an untreated feedstock showed better thermal shock resistance in molten aluminum compared with the one produced by PVA (polyvinyl alcohol) treatment.

Keywords: coating, feedstock, powder processing, thermal shock resistance, thermally spraying

Procedia PDF Downloads 258
584 Optimization of Acid Treatments by Assessing Diversion Strategies in Carbonate and Sandstone Formations

Authors: Ragi Poyyara, Vijaya Patnana, Mohammed Alam

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When acid is pumped into damaged reservoirs for damage removal/stimulation, distorted inflow of acid into the formation occurs caused by acid preferentially traveling into highly permeable regions over low permeable regions, or (in general) into the path of least resistance. This can lead to poor zonal coverage and hence warrants diversion to carry out an effective placement of acid. Diversion is desirably a reversible technique of temporarily reducing the permeability of high perm zones, thereby forcing the acid into lower perm zones. The uniqueness of each reservoir can pose several challenges to engineers attempting to devise optimum and effective diversion strategies. Diversion techniques include mechanical placement and/or chemical diversion of treatment fluids, further sub-classified into ball sealers, bridge plugs, packers, particulate diverters, viscous gels, crosslinked gels, relative permeability modifiers (RPMs), foams, and/or the use of placement techniques, such as coiled tubing (CT) and the maximum pressure difference and injection rate (MAPDIR) methodology. It is not always realized that the effectiveness of diverters greatly depends on reservoir properties, such as formation type, temperature, reservoir permeability, heterogeneity, and physical well characteristics (e.g., completion type, well deviation, length of treatment interval, multiple intervals, etc.). This paper reviews the mechanisms by which each variety of diverter functions and discusses the effect of various reservoir properties on the efficiency of diversion techniques. Guidelines are recommended to help enhance productivity from zones of interest by choosing the best methods of diversion while pumping an optimized amount of treatment fluid. The success of an overall acid treatment often depends on the effectiveness of the diverting agents.

Keywords: diversion, reservoir, zonal coverage, carbonate, sandstone

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583 The Behaviour of Laterally Loaded Piles Installed in the Sand with Enlarged Bases

Authors: J. Omer, H. Haroglu

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Base enlargement in piles was invented to enhance pile resistance in downward loading, but the contribution of an enlarged base to the lateral load resistance of a pile has not been fully exploited or understood. This paper presents a laboratory investigation of the lateral capacity and deformation response of small-scale steel piles with enlarged bases installed in dry sand. Static loading tests were performed on 24 model piles having different base-to-shaft diameter ratios. The piles were installed in a box filled with dry sand, and lateral loads were applied to the pile tops using a pulley system. The test piles had shaft diameters of 20 mm, 16 mm, and 10 mm; base diameters of 900 mm, 700 mm, and 500 mm. As a control, a pile without base enlargement was tested to allow comparisons with the enlarged base piles. Incremental maintained loads were applied until pile failure approached while recording pile head deflections with high-precision dial gauges. The results showed that the lateral capacity increased with an increase in base diameter, albeit by different percentages depending on the shaft diameters and embedment length in the sand. There was always an increase in lateral capacity with increasing embedment length. Also, it was observed that an enlarged pile base had deflected less at a given load when compared to the control pile. Therefore, the research demonstrated the benefits of lateral capacity and stability of enlarging a pile base.

Keywords: pile foundations, enlarged base, lateral loading

Procedia PDF Downloads 127
582 The Human Right to a Safe, Clean and Healthy Environment in Corporate Social Responsibility's Strategies: An Approach to Understanding Mexico's Mining Sector

Authors: Thalia Viveros-Uehara

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The virtues of Corporate Social Responsibility (CSR) are explored widely in the academic literature. However, few studies address its link to human rights, per se; specifically, the right to a safe, clean and healthy environment. Fewer still are the research works in this area that relate to developing countries, where a number of areas are biodiversity hotspots. In Mexico, despite the rise and evolution of CSR schemes, grave episodes of pollution persist, especially those caused by the mining industry. These cases set up the question of the correspondence between the current CSR practices of mining companies in the country and their responsibility to respect the right to a safe, clean and healthy environment. The present study approaches precisely such a bridge, which until now has not been fully tackled in light of Mexico's 2011 constitutional human rights amendment and the United Nation's Guiding Principles on Business and Human Rights (UN Guiding Principles), adopted by the Human Rights Council in 2011. To that aim, it initially presents a contextual framework; it then explores qualitatively the adoption of human rights’ language in the CSR strategies of the three main mining companies in Mexico, and finally, it examines their standing with respect to the UN Guiding Principles. The results reveal that human rights are included in the RSE strategies of the analysed businesses, at least at the rhetoric level; however, they do not embrace the right to a safe, clean and healthy environment as such. Moreover, we conclude that despite the finding that corporations publicly express their commitment to respect human rights, some operational weaknesses that hamper the exercise of such responsibility persist; for example, the systematic lack of human rights impact assessments per mining unit, the denial of actual and publicly-known negative episodes on the environment linked directly to their operations, and the absence of effective mechanisms to remediate adverse impacts.

Keywords: corporate social responsibility, environmental impacts, human rights, right to a safe, clean and healthy environment, mining industry

Procedia PDF Downloads 319
581 Influence of Thermal Treatments on Ovomucoid as Allergenic Protein

Authors: Nasser A. Al-Shabib

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Food allergens are most common non-native form when exposed to the immune system. Most food proteins undergo various treatments (e.g. thermal or proteolytic processing) during food manufacturing. Such treatments have the potential to impact the chemical structure of food allergens so as to convert them to more denatured or unfolded forms. The conformational changes in the proteins may affect the allergenicity of treated-allergens. However, most allergenic proteins possess high resistance against thermal modification or digestive enzymes. In the present study, ovomucoid (a major allergenic protein of egg white) was heated in phosphate-buffered saline (pH 7.4) at different temperatures, aqueous solutions and on different surfaces for various times. The results indicated that different antibody-based methods had different sensitivities in detecting the heated ovomucoid. When using one particular immunoassay‚ the immunoreactivity of ovomucoid increased rapidly after heating in water whereas immunoreactivity declined after heating in alkaline buffer (pH 10). Ovomucoid appeared more immunoreactive when dissolved in PBS (pH 7.4) and heated on a stainless steel surface. To the best of our knowledge‚ this is the first time that antibody-based methods have been applied for the detection of ovomucoid adsorbed onto different surfaces under various conditions. The results obtained suggest that use of antibodies to detect ovomucoid after food processing may be problematic. False assurance will be given with the use of inappropriate‚ non-validated immunoassays such as those available commercially as ‘Swab’ tests. A greater understanding of antibody-protein interaction after processing of a protein is required.

Keywords: ovomucoid, thermal treatment, solutions, surfaces

Procedia PDF Downloads 436
580 Effects of Canned Cycles and Cutting Parameters on Hole Quality in Cryogenic Drilling of Aluminum 6061-6T

Authors: M. N. Islam, B. Boswell, Y. R. Ginting

Abstract:

The influence of canned cycles and cutting parameters on hole quality in cryogenic drilling has been investigated experimentally and analytically. A three-level, three-parameter experiment was conducted by using the design-of-experiment methodology. The three levels of independent input parameters were the following: for canned cycles—a chip-breaking canned cycle (G73), a spot drilling canned cycle (G81), and a deep hole canned cycle (G83); for feed rates—0.2, 0.3, and 0.4 mm/rev; and for cutting speeds—60, 75, and 100 m/min. The selected work and tool materials were aluminum 6061-6T and high-speed steel (HSS), respectively. For cryogenic cooling, liquid nitrogen (LN2) was used and was applied externally. The measured output parameters were the three widely used quality characteristics of drilled holes—diameter error, circularity, and surface roughness. Pareto ANOVA was applied for analyzing the results. The findings revealed that the canned cycle has a significant effect on diameter error (contribution ratio 44.09%) and small effects on circularity and surface finish (contribution ratio 7.25% and 6.60%, respectively). The best results for the dimensional accuracy and surface roughness were achieved by G81. G73 produced the best circularity results; however, for dimensional accuracy, it was the worst level.

Keywords: circularity, diameter error, drilling canned cycle, pareto ANOVA, surface roughness

Procedia PDF Downloads 275
579 Empowering Girls and Youth in Bangladesh: Importance of Creating Safe Digital Space for Online Learning and Education

Authors: Md. Rasel Mia, Ashik Billah

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The empowerment of girls and youth in Bangladesh is a demanding issue in today's digital age, where online learning and education have become integral to personal and societal development. This abstract explores the critical importance of creating a secure online environment for girls and youth in Bangladesh, emphasizing the transformative impact it can have on their access to education and knowledge. Bangladesh, like many developing nations, faces gender inequalities in education and access to digital resources. The creation of a safe digital space not only mitigates the gender digital divide but also fosters an environment where girls and youth can thrive academically and professionally. This manuscript draws attention to the efforts through a mixed-method study to assess the current digital landscape in Bangladesh, revealing disparities in phone and internet access, online practices, and awareness of cyber security among diverse demographic groups. Moreover, the study unveils the varying levels of familial support and barriers encountered by girls and youth in their quest for digital literacy. It emphasizes the need for tailored training programs that address specific learning needs while also advocating for enhanced internet accessibility, safe online practices, and inclusive online platforms. The manuscript culminates in a call for collaborative efforts among stakeholders, including NGOs, government agencies, and telecommunications companies, to implement targeted interventions that bridge the gender digital divide and pave the way for a brighter, more equitable future for girls and youth in Bangladesh. In conclusion, this research highlights the undeniable significance of creating a safe digital space as a catalyst for the empowerment of girls and youth in Bangladesh, ensuring that they not only access but excel in the online space, thereby contributing to their personal growth and the advancement of society as a whole.

Keywords: collaboration, cyber security, digital literacy, digital resources, inclusiveness

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578 Electric Arc Furnaces as a Source of Voltage Fluctuations in the Power System

Authors: Zbigniew Olczykowski

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The paper presents the impact of work on the electric arc furnace power grid. The arc furnace operating will be modeled at different power conditions of steelworks. The paper will describe how to determine the increase in voltage fluctuations caused by working in parallel arc furnaces. The analysis of indicators characterizing the quality of electricity recorded during several cycles of measurement made at the same time at three points grid, with different power and different short-circuit rated voltage, will be carried out. The measurements analysis presented in this paper were conducted in the mains of one of the Polish steel. The indicators characterizing the quality of electricity was recorded during several cycles of measurement while making measurements at three points of different power network short-circuit power and various voltage ratings. Measurements of power quality indices included the one-week measurement cycles in accordance with the EN-50160. Data analysis will include the results obtained during the simultaneous measurement of three-point grid. This will determine the actual propagation of interference generated by the device. Based on the model studies and measurements of quality indices of electricity we will establish the effect of a specific arc on the mains. The short-circuit power network’s minimum value will also be estimated, this is necessary to limit the voltage fluctuations generated by arc furnaces.

Keywords: arc furnaces, long-term flicker, measurement and modeling of power quality, voltage fluctuations

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577 Estimation of Residual Stresses in Thick Walled Cylinder by Radial Basis Artificial Neural

Authors: Mohammad Heidari

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In this paper a method for high strength steel is proposed of residual stresses in autofrettaged tubes by combination of artificial neural networks is presented. Many different thick walled cylinders that were subjected to different conditions were studied. At first, the residual stress is calculated by analytical solution. Then by changing of the parameters that influenced in residual stresses such as percentage of autofrettage, internal pressure, wall ratio of cylinder, material property of cylinder, bauschinger and hardening effect factor, a neural network is created. These parameters are the input of network. The output of network is residual stress. Numerical data, employed for training the network and capabilities of the model in predicting the residual stress has been verified. The output obtained from neural network model is compared with numerical results, and the amount of relative error has been calculated. Based on this verification error, it is shown that the radial basis function of neural network has the average error of 2.75% in predicting residual stress of thick wall cylinder. Further analysis of residual stress of thick wall cylinder under different input conditions has been investigated and comparison results of modeling with numerical considerations shows a good agreement, which also proves the feasibility and effectiveness of the adopted approach.

Keywords: thick walled cylinder, residual stress, radial basis, artificial neural network

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576 Surface Engineering and Characterization of S-Phase Formed in AISI 304 By Low-Temperature Nitrocarburizing

Authors: Jeet Vijay Sah, Alphonsa Joseph, Pravin Kumari Dwivedi, Ghanshyam Jhala, Subroto Mukherjee

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AISI 304 is known for its corrosion resistance which comes from Cr that forms passive Cr₂O₃ on the surface. But its poor hardness makes it unsuitable for applications where the steel also requires high wear resistance. This can be improved by surface hardening using nitrocarburizing processes, which form ε-Fe2-3N, γ’-Fe4N, nitrides, and carbides of Cr and Fe on the surface and subsurface. These formed phases give the surface greater hardness, but the corrosion resistance drops because of the lack of Cr2O3 passivation as a result. To overcome this problem, plasma nitrocarburizing processes are being developed where the process temperatures are kept below 723 K to avoid Cr-N precipitation. In the presented work, low-temperature pulsed-DC plasma nitrocarburizing utilizing a discharge of N₂-H₂-C₂H₂ at 500 Pa with varying N₂:H₂ ratios was conducted on AISI 304 samples at 673 K. The process durations were also varied, and the samples were characterized by microindentation using Vicker’s hardness tester, corrosion resistances were established from electrochemical impedance studies, and corrosion potentials and corrosion currents were obtained by potentiodynamic polarization testing. XRD revealed S-phase, which is a supersaturated solid solution of N and C in the γ phase. The S-phase was observed to be composed of the expanded phases of γ; γN, γC, and γ’N and ε’N phases. Significant improvement in surface hardness was achieved after every process, which is attributed to the S-phase. Corrosion resistance was also found to improve after the processes. The samples were also characterized by XPS, SEM, and GDOES.

Keywords: AISI 304, surface engineering, nitrocarburizing, S-phase

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575 A Perspective on Teaching Mathematical Concepts to Freshman Economics Students Using 3D-Visualisations

Authors: Muhammad Saqib Manzoor, Camille Dickson-Deane, Prashan Karunaratne

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Cobb-Douglas production (utility) function is a fundamental function widely used in economics teaching and research. The key reason is the function's characteristics to describe the actual production using inputs like labour and capital. The characteristics of the function like returns to scale, marginal, and diminishing marginal productivities are covered in the introductory units in both microeconomics and macroeconomics with a 2-dimensional static visualisation of the function. However, less insight is provided regarding three-dimensional surface, changes in the curvature properties due to returns to scale, the linkage of the short-run production function with its long-run counterpart and marginal productivities, the level curves, and the constraint optimisation. Since (freshman) learners have diverse prior knowledge and cognitive skills, the existing “one size fits all” approach is not very helpful. The aim of this study is to bridge this gap by introducing technological intervention with interactive animations of the three-dimensional surface and sequential unveiling of the characteristics mentioned above using Python software. A small classroom intervention has helped students enhance their analytical and visualisation skills towards active and authentic learning of this topic. However, to authenticate the strength of our approach, a quasi-Delphi study will be conducted to ask domain-specific experts, “What value to the learning process in economics is there using a 2-dimensional static visualisation compared to using a 3-dimensional dynamic visualisation?’ Here three perspectives of the intervention were reviewed by a panel comprising of novice students, experienced students, novice instructors, and experienced instructors in an effort to determine the learnings from each type of visualisations within a specific domain of knowledge. The value of this approach is key to suggesting different pedagogical methods which can enhance learning outcomes.

Keywords: cobb-douglas production function, quasi-Delphi method, effective teaching and learning, 3D-visualisations

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574 Countering Violent Extremism in Pakistan: Case Study of Sectarian Divide

Authors: Muqarrab Akbar

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Pakistan is considered as a state confronting different internal and external challenges. Extremism is one of the most vital internal challenges faced by Pakistani society. The state’s contradictory policies, political instability, socio-economic injustice, absence of the rule of law are the major reasons behind the proliferation of violence and extremism in society. The fall of the Shah of Iran, the Iranian revolution, the 1979 Afghan war of 1979, the emergence of Al-Qaeda, Talibanisation, war against terrorism, and involvement of Saudia and Iran have further aggravated the culture of violence and extremism in Pakistan. The absence of a narrative of peaceful coexistence and harmony has created a vacuum for youth in Pakistani society. In the contemporary era, civil society and the government of Pakistan has initiated different steps to introduce a narrative to counter violent extremism. These narratives have helped a lot in creating community resilience to promote peace and harmony among Pakistani society in general and to bridge the gap between the Sunni Shia divide in particular. This paper will highlight those factors in detail that threw the society into extremism and violence, particularly with reference to Sunni Shia divide in Pakistan. This paper explores the impact of sectarian violence in Pakistan and highlights the different initiatives and their impacts on Pakistani society at large. A quantitative method has been adopted to explore the results. Empirical study used in the paper was based on the survey conducted by distributing questionnaires among 300 people from both community Sunni and Shia in Pakistan. Some interviews of the religious scholars of both communities are also conducted for this research. The recent developments on the government level and society levels have created community resilience. The results of the survey show that Pakistani society in the contemporary era is more peaceful and tolerant as compared to the past. The research concludes that the counter-narrative approach is positively affecting the peaceful environment in Pakistan.

Keywords: extremism, Pakistan, Shia, Sunni, violence

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573 Effects of the Slope Embankment Variation on Influence Areas That Causes the Differential Settlement around of Embankment

Authors: Safitri W. Nur, Prathisto Panuntun L. Unggul, M. Ivan Adi Perdana, R. Dary Wira Mahadika

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On soft soil areas, high embankment as a preloading needed to improve the bearing capacity of the soil. For sustainable development, the construction of embankment must not disturb the area around of them. So, the influence area must be known before the contractor applied their embankment design. For several cases in Indonesia, the area around of embankment construction is housing resident and other building. So that, the influence area must be identified to avoid the differential settlement occurs on the buildings around of them. Differential settlement causes the building crack. Each building has a limited tolerance for the differential settlement. For concrete buildings, the tolerance is 0,002 – 0,003 m and for steel buildings, the tolerance is 0,006 – 0,008 m. If the differential settlement stands on the range of that value, building crack can be avoided. In fact, the settlement around of embankment is assumed as zero. Because of that, so many problems happen when high embankment applied on soft soil area. This research used the superposition method combined with plaxis analysis to know the influences area around of embankment in some location with the differential characteristic of the soft soil. The undisturbed soil samples take on 55 locations with undisturbed soil samples at some soft soils location in Indonesia. Based on this research, it was concluded that the effects of embankment variation are if more gentle the slope, the influence area will be greater and vice versa. The largest of the influence area with h initial embankment equal to 2 - 6 m with slopes 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8 is 32 m from the edge of the embankment.

Keywords: differential settlement, embankment, influence area, slope, soft soil

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572 Study on High Performance Fiber Reinforced Concrete (HPFRC) Beams on Subjected to Cyclic Loading

Authors: A. Siva, K. Bala Subramanian, Kinson Prabu

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Concrete is widely used construction materials all over the world. Now a day’s fibers are used in this construction due to its advantages like increase in stiffness, energy absorption, ductility and load carrying capacity. The fiber used in the concrete to increases the structural integrity of the member. It is one of the emerging techniques used in the construction industry. In this paper, the effective utilization of high-performance fiber reinforced concrete (HPFRC) beams has been experimental investigated. The experimental investigation has been conducted on different steel fibers (Hooked, Crimpled, and Hybrid) under cyclic loading. The behaviour of HPFRC beams is compared with the conventional beams. Totally four numbers of specimens were cast with different content of fiber concrete and compared conventional concrete. The fibers are added to the concrete by base volume replacement of concrete. The silica fume and superplasticizers were used to modify the properties of concrete. Single point loading was carried out for all the specimens, and the beam specimens were subjected to cyclic loading. The load-deflection behaviour of fibers is compared with the conventional concrete. The ultimate load carrying capacity, energy absorption and ductility of hybrid fiber reinforced concrete is higher than the conventional concrete by 5% to 10%.

Keywords: cyclic loading, ductility, high performance fiber reinforced concrete, structural integrity

Procedia PDF Downloads 255