Search results for: bridge inspection

Authors: Huy Q. Tran, Jungwon Huh, Kiseok Kwak, Choonghyun Kang

Abstract:

Infrared thermography (IRT) technique has been proven to be a good method for nondestructive evaluation of concrete material. In the building, a broad range of applications has been used such as subsurface defect inspection, energy loss, and moisture detection. The purpose of this research is to consider the qualitative and quantitative performance of reinforced concrete deteriorations using active infrared thermography technique. An experiment of three different heating regimes was conducted on a concrete slab in the laboratory. The thermal characteristics of the IRT method, i.e., absolute contrast and observation time, are investigated. A linear relationship between the observation time and the real depth was established with a well linear regression R-squared of 0.931. The results showed that the absolute contrast above defective area increases with the rise of the size of delamination and the heating time. In addition, the depth of delamination can be predicted by using the proposal relationship of this study.

Keywords: concrete building, infrared thermography, nondestructive evaluation, subsurface delamination

Procedia PDF Downloads 283

Authors: I. Touaїbia, E. Azzag, O. Narjes

Abstract:

Power supply networks are growing continuously and their reliability is getting more important than ever. The complexity of the whole network comprises numerous components that can fail and interrupt the power supply for the end user. Underground distribution systems are normally exposed to permanent faults, due to specific construction characteristics. In these systems, visual inspection cannot be performed. In order to enhance service restoration, accurate fault location techniques must be applied. This paper describes the different faults that affect the underground distribution system of SONELGAZ (National Society of Electricity and Gas of Algeria), and cable fault location procedure with impulse reflection method (TDR), based in the analyses of the cable response of the electromagnetic impulse, allows cable fault prelocation. The results are obtained from real test in the underground distribution feeder from electrical network of energy distribution company of Souk-Ahras, in order to know the influence of cable characteristics in the types and frequency of faults.

Keywords: distribution networks, fault location, TDR, underground cable

Procedia PDF Downloads 533

Authors: Sandhya Armoogum

Abstract:

In distributed systems and in open systems such as the Internet, often mobile code has to run on unknown and potentially hostile hosts. Mobile code such as a mobile agent is vulnerable when executing on remote hosts. The mobile agent may be subjected to various attacks such as tampering, inspection, and replay attack by a malicious host. Much research has been done to provide solutions for various security problems, such as authentication of mobile agent and hosts, integrity and confidentiality of the data carried by the mobile agent. Many of such proposed solutions in literature are not suitable for open systems whereby the mobile code arrives and executes on a host which is not known and trusted by the mobile agent owner. In this paper, we propose the adoption of the reference monitor by hosts in an open system for providing trust and security for mobile code execution. A secure protocol for the distribution of the reference monitor entity is described. This reference monitor entity on the remote host may also provide several security services such as authentication and integrity to the mobile code.

Keywords: security, mobile agents, reference monitor, trust

Procedia PDF Downloads 440

Authors: Thoudam Jomita Devi

Abstract:

This paper is an attempt to analyze the problems of translating Manipuri folktales into English and the strategies deployed. In Manipuri, folktales are known as Fungawari/Phungawari, which is similar to a western bed time story. The work is with the special reference to folktales of Meetei community. Meetei are the majority ethnic group of Manipur, India. For this paper’s purpose, two folktales Shandrembi Cheisra and Pebet will be chosen for analysis and discussion. The translation of folktales can contribute to intercultural communication and bridge the gap between the generations. Translating Manipuri Folktales is problematic on both cultural and linguistic levels. Therefore, the aim of this analysis is to understand, how the idea of André Lefevere (1992) translation could be implicated in translating Manipuri folktales.

Keywords: cultural, folktales, intercultural, interlingual, translation

Procedia PDF Downloads 187

Authors: Shashank Gupta, Carlos Cid, William John Munro

Abstract:

Quantum distillation is the task of concentrating quantum correlations present in N imperfect copies to M perfect copies (M < N) using free operations by involving all P the parties sharing the quantum correlation. We present a threshold quantum distillation task where the same objective is achieved but using lesser number of parties (K < P). In particular, we give an exact local filtering operations by the participating parties sharing high dimension multipartite entangled state to distill the perfect quantum correlation. Later, we bridge a connection between threshold quantum entanglement distillation and quantum steering distillation and show that threshold distillation might work in the scenario where general distillation protocol like DEJMPS does not work.

Keywords: quantum networks, quantum distillation, quantum key distribution, entanglement distillation

Procedia PDF Downloads 45

Authors: Manoj Reghu, Prabhu Rajagopal, C. V. Krishnamurthy, Krishnan Balasubramaniam

Abstract:

A thorough understanding of guided ultrasonic wave behavior in structures is essential for the application of existing Non Destructive Evaluation (NDE) technologies, as well as for the development of new methods. However, the analysis of guided wave phenomena is challenging because of their complex dispersive and multimodal nature. Although numerical solution procedures have proven to be very useful in this regard, the increasing complexity of features and defects to be considered, as well as the desire to improve the accuracy of inspection often imposes a large computational cost. Hybrid models that combine numerical solutions for wave scattering with faster alternative methods for wave propagation have long been considered as a solution to this problem. However usually such models require modification of the base code of the solution procedure. Here we aim to develop Generic Hybrid models that can be directly applied to any two different solution procedures. With this goal in mind, a Numerical Hybrid model and an Analytical-Numerical Hybrid model has been developed. The concept and implementation of these Hybrid models are discussed in this paper.

Keywords: guided ultrasonic waves, Finite Element Method (FEM), Hybrid model

Procedia PDF Downloads 465

Authors: K. Piórkowska

Abstract:

The overarching aim of the paper is to incorporate the micro-foundations perspective in strategic management and offering possibilities to bridge the macro–micro divide, to review the concept of habits, as well as to propose research findings and directions in terms of further exploring the habit construct and its impact on higher epistemological level phenomena (for instance organizational routines, which is a domain inherently multilevel in nature). To realize this aim, the following sections have been developed: (1) habits’ origins, (2) habits – cognitive constellations, (3) interrelationships between habits and mental representations, intentions, (4) habits and organizational routines, and (5) habits and routines linkages with adaptation. The conclusions that have been made support recent and current studies linking the level of individual heterogeneous agents with the level of macro (organizational) outcomes.

Keywords: behaviorism, habits, micro-foundations, routines

Procedia PDF Downloads 258

Authors: Radwa Saad

Abstract:

The Sahara is normatively treated as a barrier separating “two Africas"; one to the North with closer affinity to the Arab world, and one to the South that encompasses a diverse range of racial, ethnic and religious groups, commonly referred to as "Sub-Saharan Africa". This dichotomy however was challenged by many anticolonial leaders and intellectuals seeking to advance counter-hegemonic narratives that treat the Sahara as a bridge facilitating a long history of exchange, collaboration, and fusion between different civilizations on the continent. This paper reexamines the discourses governing the geographic distinction between North Africa and Sub-Saharan Africa. It argues that demarcating the African continent along the lines of the Sahara is part-and-parcel of a Euro-centric spatial imaginary that has served to enshrine a racialized global hierarchy of power. By drawing on Edward Said’s concept of ‘imagined geography’ and Charles Mill’s notion of “the racial contract”, it demonstrates how spatial boundaries often coincide with racial epistemologies to reinforce certain geopolitical imaginaries, whilst silencing others. It further draws on the works of two notable post-colonial figures - Gamal Abdel Nasser and Leopold Senghor - to explore alternative spatial imaginaries while highlighting some of the tensions embedded in advancing a trans-Saharan political project. Firstly, it deconstructs some of the normative claims used to justify the distinction between North and “sub-Saharan” Africa across political, literary and disciplinary boundaries. Secondly, it draws parallels between Said’s and Mills’ work to demonstrate how geographical boundaries and demarcations have been constructed to create racialized subjects and reinforce a hierarchy of color that favors European standpoints and epistemologies. Third, it draw on Leopard Senghor’s The Foundations of Africanité and Gamal Abdel Nasser’s The Philosophy of the Egyptian Revolution to examine some of the competing strands of unity that emerged out of the Saharan discourse. In these texts, one can identify a number of convergences and divergences in how post-colonial African elites attempts to reclaim and rearticulate the function of the Sahara along different epistemic, political and cultural premises. It concludes with reflections on some of the policy challenges that emerge from reinforcing the Saharan divide, particularly in the realm of peace and security.

Keywords: regional integration, politics of knowledge production, arab-african relations, african solutions to african problems

Procedia PDF Downloads 86

Authors: Elizabeth Watson, Sara Vogt

Abstract:

The transition from high school to college can be an exciting and confusing time for many students, especially college students with disabilities. In 1983, the University of Wisconsin-Whitewater created a Summer Transition Program (STP) for such students as part of a US Department of Education Demonstration Grant. This program offers incoming students the opportunity to take 2 college courses and live on campus for 4 weeks to help introduce and familiarize them with typical college expectations and support services. Over the past 30 years, 48% of the students have graduated, exceeding the national college graduation rate for students with disabilities. This mixed methods longitudinal study will discuss how this program has increased retention and graduation rates, and success in the co-curricular and living environments for students with disabilities.

Keywords: disability, transition, post-secondary education, retention

Procedia PDF Downloads 292

Authors: Kitti Leangkrua

Abstract:

This paper presents a risk-based maintenance strategy of a power transformer in order to optimize operating and maintenance costs. The methodology involves the study and preparation of a database for the collection the technical data and test data of a power transformer. An evaluation of the overall condition of each transformer is performed by a program developed as a result of the measured results; in addition, the calculation of the main equipment separation to the overall condition of the transformer (% HI) and the criteria for evaluating the importance (% ImI) of each location where the transformer is installed. The condition assessment is performed by analysis test data such as electrical test, insulating oil test and visual inspection. The condition of the power transformer will be classified from very poor to very good condition. The importance is evaluated from load criticality, importance of load and failure consequence. The risk matrix is developed for evaluating the risk of each power transformer. The high risk power transformer will be focused firstly. The computerized program is developed for practical use, and the maintenance strategy of a power transformer can be effectively managed.

Keywords: asset management, risk-based maintenance, power transformer, health index

Procedia PDF Downloads 306

Authors: Vidhi Jain

Abstract:

Communication between speakers and non-speakers of American Sign Language (ASL) can be problematic, inconvenient, and expensive. This project attempts to bridge the communication gap by designing a portable glove that captures the user’s ASL gestures and outputs the translated text on a smartphone. The glove is equipped with flex sensors, contact sensors, and a gyroscope to measure the flexion of the fingers, the contact between fingers, and the rotation of the hand. The glove’s Arduino UNO microcontroller analyzes the sensor readings to identify the gesture from a library of learned gestures. The Bluetooth module transmits the gesture to a smartphone. Using this device, one day speakers of ASL may be able to communicate with others in an affordable and convenient way.

Keywords: sign language, morse code, convolutional neural network, American sign language, gesture recognition

Procedia PDF Downloads 63

Authors: Christopher Oyediran, Nicola Ubayasiri, Christopher Gough

Abstract:

Splenic artery aneurysms are often clinically occult, occasionally identified incidentally with imaging. The pathogenesis of aneurysms is complex, but certain factors are thought to contribute to their development. Given the potential fatal complications of rupture, a high index of suspicion is required to make an early diagnosis. We present a case of a 36-year-old female with a history of endometriosis and multiple sclerosis who presented to the Emergency Department with sudden onset epigastric pain and collapse. On arrival, she was pale and clammy with profound tachycardia and hypotension. An ultrasound done in the resuscitation department revealed abdominal free fluid. She was resuscitated with blood and transferred for emergent laparotomy. Laparotomy revealed massive haemoperitoneum from the spleen. She underwent emergency splenectomy and inspection of the spleen revealed a splenic artery aneurysm. She received our massive transfusion protocol followed by a short stay on ITU, making a good post-operative recovery and was discharged home a week later.

Keywords: aneurysm, human chorionic gonadotrophin (hCG), resuscitation, laparotomy

Procedia PDF Downloads 431

Authors: Andika Bagaskara, Andhika Rizki Pratama, Lalu Arya Repatmaja, Septhian Ditaputra Raharja

Abstract:

The power transformer is one of the critical things in system transmission. Regular testing of the power transformer is very important to maintain the reliability of the power. One of the causes of the failure of the transformer is the breakdown of insulation caused by the presence of voids in the equipment that is electrified. As a result of the voids that occur in this power transformer equipment, it can cause partial discharge. Several methods were used to determine the occurrence of damage to the power transformer equipment, such as Sweep Frequency Response Analysis (SFRA) and Tan Delta. In Inter Bus Transformer (IBT) 500/150 kV Cirata Extra High Voltage (EHV) Substation, a breakdown occurred in the T-phase tertiary bushing. From the lessons learned in this case, a complete electrical test was carried out. From the results of the complete electrical test, there was a suspicion of deterioration in the post-breakdown SFRA results. After overhaul and inspection, traces of voids were found on the tertiary bushing, which indicated a breakdown in the tertiary bushing of the IBT 500/150kV Cirata Substation transformer.

Keywords: void, bushing, SFRA, Tan Delta

Procedia PDF Downloads 141

Authors: V. Makis, L. Jafari

Abstract:

In this paper, we develop an optimal Bayesian chart to control the expected number of defects per inspection unit in production processes with long production runs. We formulate this control problem in the optimal stopping framework. The objective is to determine the optimal stopping rule minimizing the long-run expected average cost per unit time considering partial information obtained from the process sampling at regular epochs. We prove the optimality of the control limit policy, i.e., the process is stopped and the search for assignable causes is initiated when the posterior probability that the process is out of control exceeds a control limit. An algorithm in the semi-Markov decision process framework is developed to calculate the optimal control limit and the corresponding average cost. Numerical examples are presented to illustrate the developed optimal control chart and to compare it with the traditional u-chart.

Keywords: Bayesian u-chart, economic design, optimal stopping, semi-Markov decision process, statistical process control

Procedia PDF Downloads 573

Authors: Varsha Singh, Shraddha Prajapati, M. B. Kiran

Abstract:

Texture identification is useful in predicting the functionality of a component. Many of the existing texture identification methods are of contact in nature, which limits its measuring speed. These contact measurement techniques use a diamond stylus and the diamond stylus being sharp going to damage the surface under inspection and hence these techniques can be used in statistical sampling. Though these contact methods are very accurate, they do not give complete information for full characterization of surface. In this context, the presented method assumes special significance. The method uses a relatively low cost vision system for image acquisition. Software is developed based on wavelet transform, for analyzing texture images. Specimens are made using different manufacturing process (shaping, grinding, milling etc.) During experimentation, the specimens are illuminated using proper lighting and texture images a capture using CCD camera connected to the vision system. The software installed in the vision system processes these images and subsequently identify the texture of manufacturing processes.

Keywords: diamond stylus, manufacturing process, texture identification, vision system

Procedia PDF Downloads 289

Authors: Suppara Charoenpoom

Abstract:

The objectives of this research was to design and develop a quality management of the school buildings and environment. A quantitative and qualitative mixed research methodology was used. The population sample included 14 directors of primary schools. Two research tools were used. The first research tool included an in-depth interview and questionnaire. The second research tool included the Quality Business Process and Quality Work Procedure, and a Key Performance Indicator of each activity. The statistics included mean and standard deviation. The findings for the development of a quality management process of buildings and environment administration of the basic schools consisted of one quality business process (QBP) and seven quality work processes (QWP). The result from the experts’ evaluation revealed that the process and implementation of quality management of the school buildings and environment has passed the inspection process with consensus. This implies that the process of quality management of the school buildings and environment is suitable for implementation. Moreover, the level of agreement in the feasibility of the implementation of this plan had the mean in the range of 0.64-1.00 which suggests the design of the new plan is acceptable.

Keywords: process, building, environment, management

Procedia PDF Downloads 239

Authors: Yu-Lin Shen, Ming-Kuen Chang

Abstract:

In addition to a considerable amount of machinery and equipment, intricacies of the transmission pipeline exist in Petrochemical plants. Long term corrosion may lead to pipeline thinning and rupture, causing serious safety concerns. With the advances in non-destructive testing technology, more rapid and long-range ultrasonic detection techniques are often used for pipeline inspection, EMAT without coupling to detect, it is a non-contact ultrasonic, suitable for detecting elevated temperature or roughened e surface of line. In this study, we prepared artificial defects in pipeline for Electromagnetic Acoustic Transducer Testing (EMAT) to survey the relationship between the defect location, sizing and the EMAT signal. It was found that the signal amplitude of EMAT exhibited greater signal attenuation with larger defect depth and length.. In addition, with bigger flat hole diameter, greater amplitude attenuation was obtained. In summary, signal amplitude attenuation of EMAT was affected by the defect depth, defect length and the hole diameter and size.

Keywords: EMAT, artificial defect, NDT, ultrasonic testing

Procedia PDF Downloads 333

Authors: Valon Shkodra

Abstract:

In our paper, we will give an overview of the cultural heritage and tourism in Kosovo. Kosovo has a history, culture, tradition and architecture that are different from those of other countries in the region, and each country has its own characteristics and peculiarities. In this paper, we will mainly present the situation of cultural heritage and its interpretation. The research is based on fieldwork and the aim of the research is to live the situation of cultural heritage and tourism. The reason why we chose this topic is that cultural heritage and tourism are now the most important industry developing many countries in the world. Besides the benefits that tourism brings, it also has an impact on the preservation, protection and promotion of culture in general. Kosovo, with its cultural diversity and very good geographical location, is also very well suited to develop these two areas as a bridge to each other. The cultural heritage holds traces from the earliest eras and shows a diversity of different civilizations that have just begun to be explored and presented.

Keywords: cultural heritage, economy, tourism, development, institutions, protection

Procedia PDF Downloads 224

Authors: Dongyeob Han, Jungwon Huh, Quang Huy Tran, Choonghyun Kang

Abstract:

Unmanned Aerial Vehicles (UAVs) have been used for surveillance, monitoring, inspection, and mapping. In this paper, we present a systematic approach for automatic registration of UAV images for monitoring facilities such as building, green house, and civil structures. The two-step process is applied; 1) an image matching technique based on SURF (Speeded up Robust Feature) and RANSAC (Random Sample Consensus), 2) bundle adjustment of multi-temporal images. Image matching to find corresponding points is one of the most important steps for the precise registration of multi-temporal images. We used the SURF algorithm to find a quick and effective matching points. RANSAC algorithm was used in the process of finding matching points between images and in the bundle adjustment process. Experimental results from UAV images showed that our approach has a good accuracy to be applied to the change detection of facility.

Keywords: building, image matching, temperature, unmanned aerial vehicle

Procedia PDF Downloads 292

Authors: Abdurraheem A. Yakub

Abstract:

Housing is one of the needs of mankind and is one of the best indicators of a person’s standard of living. This research was set out to analyze the housing qualities and conditions in Kano. Primary data was collected through both Personal observations where the researcher carried out an inspection of the study area prior to interview/implementation of questionnaires and took into consideration the type of housing units, construction materials and services available as well as the environmental condition of the study area. This was followed by an interview which was done through personal contact with the various people related to the study. In the course of doing that, questions were asked orally and notes were taken to record the responses. Thereafter, the Questionnaire was implemented which was earlier designed to elicit information from households in the study area using well-structured questions related to the type of facilities provided in the housing unit, types of houses and response with regard to quality of their houses and neighborhoods, tenure of house. The research work looked at the prevailing housing qualities and conditions and the state of the existing facilities and amenities within the environment and offered recommendations on policies and measures that could help improve the situation.

Keywords: housing provision, housing quality, housing standard, housing condition, housing affordability and housing facilities

Procedia PDF Downloads 345

Authors: Muhammad Ali Sarwar, Muhammad Farooq, Nayab Hassan, Hammad Hassan

Abstract:

Pakistan is highly recognized for its agriculture and is well known for producing substantial amounts of wheat, cotton, and sugarcane. However, some factors contribute to a decline in crop quality and a reduction in overall output. One of the main factors contributing to this decline is the presence of weed and its late detection. This process of detection is manual and demands a detailed inspection to be done by the farmer itself. But by the time detection of weed, the farmer will be able to save its cost and can increase the overall production. The focus of this research is to identify and classify the four main types of weeds (Small-Flowered Cranesbill, Chick Weed, Prickly Acacia, and Black-Grass) that are prevalent in our region’s major crops. In this work, we implemented three different deep learning techniques: YOLO-v5, Inception-v3, and Deep CNN on the same Dataset, and have concluded that deep convolutions neural network performed better with an accuracy of 97.45% for such classification. In relative to the state of the art, our proposed approach yields 2% better results. We devised the architecture in an efficient way such that it can be used in real-time.

Keywords: deep convolution networks, Yolo, machine learning, agriculture

Procedia PDF Downloads 117

Authors: Piyush Swami, Bijaya Ketan Panigrahi, Sneh Anand, Manvir Bhatia, Tapan Gandhi

Abstract:

Visual inspection of electroencephalogram (EEG) signals to detect epileptic signals is very challenging and time-consuming task even for any expert neurophysiologist. This problem is most challenging in under-developed and developing countries due to shortage of skilled neurophysiologists. In the past, notable research efforts have gone in trying to automate the seizure detection process. However, due to high false alarm detections and complexity of the models developed so far, have vastly delimited their practical implementation. In this paper, we present a novel scheme for epileptic seizure detection using empirical mode decomposition technique. The intrinsic mode functions obtained were then used to calculate the standard deviations. This was followed by probability density based classifier to discriminate between non-ictal and ictal patterns in EEG signals. The model presented here demonstrated very high classification rates ( > 97%) without compromising the statistical performance. The computation timings for each testing phase were also very low ( < 0.029 s) which makes this model ideal for practical applications.

Keywords: electroencephalogram (EEG), epilepsy, ictal patterns, empirical mode decomposition

Procedia PDF Downloads 406

Authors: Babatunde Joel Todowede

Abstract:

The challenges of nation building and sustainable development have continued to feature prominently in the general reckoning of problems of underdevelopment in the developing countries of the world. Thus, since the attainment of political independence from the British colonial administration in 1960, one of the critical thrusts of central governance in Nigeria has been the particular policy attention of the educational sector. Of course, education is perceived as the logical bridge between the two contrasting worlds of underdevelopment and development, hence, its fundamental importance. The various public policies and practices associated with the Nigerian educational sector are specifically elaborated and critically assessed in this paper. In the final analysis, it is concluded that the educational sector should be better configured and managed in ways that the wider challenges of nation-building and sustainable development are effectively tractable.

Keywords: Nigeria education, educational need, educational plans and policies, educational challenges, corrective measures, emerging economy

Procedia PDF Downloads 373

Authors: Thidarath Rungruangchaikongmi, Duangsamorn Rungsawanpho

Abstract:

This research aims to investigate the efficiency of storehouse management and collect problems of the process of storehouse work of Faculty of Management Science, Suan Sunandha Rajabhat University. The subjects consisting of head of storehouse section and staffs, sampled through the Convenience Sampling Technique for 97 sampling were included in the study and the Content Analysis technique was used in analysis of data. The results of the study revealed that the management efficiency of the storehouse work on the part of work process was found to be relevant to university’s rules and regulations. The delay of work in particular steps had occurred due to more rules and regulations or practice guidelines were issued for work transparency and fast and easy inspection and control. The key problem of the management of storehouse work fell on the lack of knowledge and understanding regarding university’s rules and regulations or practice guidelines of the officers.

Keywords: efficiency of storehouse management, faculty of management science, process of storehouse work, Suan Sunandha Rajabhat University

Procedia PDF Downloads 300

Authors: Anek Apipatkul, Paphakorn Pitayachaval

Abstract:

Preventive maintenance is a standardized procedure to control and prevent risky problems affecting production in order to increase work efficiency. Machine monitoring also routinely works to collect data for a scheduling maintenance period. This paper is to present the application of machine monitoring by using the internet of things (IOTs) and a lean technique in order to manage with complex maintenance tasks of an automated plastic granule packing machine. To organize the preventive maintenance, there are several processes that the machine monitoring was applied, starting with defining a clear scope of the machine, establishing standards in maintenance work, applying a just-in-time (JIT) technique for timely delivery in the maintenance work, solving problems on the floor, and also improving the inspection process. The result has shown that wasted time was reduced, and machines have been operated as scheduled. Furthermore, the efficiency of the scheduled maintenance period was increased by 95%.

Keywords: internet of things, preventive maintenance, machine monitoring, lean technique

Procedia PDF Downloads 102

Authors: Mohammed Jibrin Ndejiko

Abstract:

Modern and current models such as flow cell technology which enhances a non-destructive growth and inspection of the sessile microbial communities revealed a great understanding of biofilms. A continuous flow system was designed to evaluate possibility of biofilm formation by Escherichia coli DH5α on the stainless steel (type 304) under continuous nutrient supply. The result of the colony forming unit (CFU) count shows that bacterial attachment and subsequent biofilm formation on stainless steel coupons with average surface roughness of 1.5 ± 1.8 µm and 2.0 ± 0.09 µm were both significantly higher (p ≤ 0.05) than those of the stainless steel coupon with lower surface roughness of 0.38 ± 1.5 µm. These observations support the hypothesis that surface profile is one of the factors that influence biofilm formation on stainless steel surfaces. The SEM and FESEM micrographs of the stainless steel coupons also revealed the attached Escherichia coli DH5α biofilm and dehydrated extracellular polymeric substance on the stainless steel surfaces. Thus, the fabricated flow system represented a very useful tool to study biofilm formation under continuous nutrient supply.

Keywords: biofilm, flowcell, stainless steel, coupon

Procedia PDF Downloads 318

Authors: Esteban Morales Murillo, Ephraim Mokgothu

Abstract:

This paper presents the findings of a study conducted to investigate the wall thinning in a piping system carrying a mix of hydrocarbons in a petrochemical plant. A detailed investigation including optical inspection and several characterisation techniques such as optical microscopy, SEM/EDX, and XRF/C-S analyses was conducted. The examinations revealed that the wall thinning in the piping system was a result of high-temperature H2/H2S corrosion caused by a susceptible material for this mechanism and operating parameters and effluent concentrations beyond the prescribed limits. The sulfide layers found to testify to the large amounts of H2S that led to material degradation. Deposit analysis revealed that it consisted primarily of carbon, oxygen, iron, chromium and sulfur. Metallographic examinations revealed that the attack initiated from the internal surface and that spheroidization of carbides did occur. The article discusses in detail the contribution failure factors on the Couper-Gorman H2/H2S curves to draw conclusions. Recommendations based on the above findings are also discussed.

Keywords: corrosion, Couper-Gorman, high-temperature corrosion, sulfidation, wall thinning, piping system

Procedia PDF Downloads 385

Authors: Elia Favarelli, Enrico Testi, Andrea Giorgetti

Abstract:

Autonomous structural health monitoring (SHM) of many structures and bridges became a topic of paramount importance for maintenance purposes and safety reasons. This paper proposes a set of machine learning (ML) tools to perform automatic feature selection and detection of anomalies in a bridge from vibrational data and compare different feature extraction schemes to increase the accuracy and reduce the amount of data collected. As a case study, the Z-24 bridge is considered because of the extensive database of accelerometric data in both standard and damaged conditions. The proposed framework starts from the first four fundamental frequencies extracted through operational modal analysis (OMA) and clustering, followed by density-based time-domain filtering (tracking). The fundamental frequencies extracted are then fed to a dimensionality reduction block implemented through two different approaches: feature selection (intelligent multiplexer) that tries to estimate the most reliable frequencies based on the evaluation of some statistical features (i.e., mean value, variance, kurtosis), and feature extraction (auto-associative neural network (ANN)) that combine the fundamental frequencies to extract new damage sensitive features in a low dimensional feature space. Finally, one class classifier (OCC) algorithms perform anomaly detection, trained with standard condition points, and tested with normal and anomaly ones. In particular, a new anomaly detector strategy is proposed, namely one class classifier neural network two (OCCNN2), which exploit the classification capability of standard classifiers in an anomaly detection problem, finding the standard class (the boundary of the features space in normal operating conditions) through a two-step approach: coarse and fine boundary estimation. The coarse estimation uses classics OCC techniques, while the fine estimation is performed through a feedforward neural network (NN) trained that exploits the boundaries estimated in the coarse step. The detection algorithms vare then compared with known methods based on principal component analysis (PCA), kernel principal component analysis (KPCA), and auto-associative neural network (ANN). In many cases, the proposed solution increases the performance with respect to the standard OCC algorithms in terms of F1 score and accuracy. In particular, by evaluating the correct features, the anomaly can be detected with accuracy and an F1 score greater than 96% with the proposed method.

Keywords: anomaly detection, frequencies selection, modal analysis, neural network, sensor network, structural health monitoring, vibration measurement

Procedia PDF Downloads 123

Authors: Shijie Liu, Jehnming Lin

Abstract:

This study mainly discussed the mechanical properties of selective laser sintered 304L stainless steel powder specimen. According to a single layer specimen sintering, the microstructure and porosity were observed to find out the proper sintering parameters. A multi-layer sintering experiment was conducted. Based on the microstructure and the integration between layers, the suitable parameters were found out. Finally, the sintered specimens were examined by metallographical inspection, hardness test, tensile test, and surface morphology measurement. The structure of the molten powder coated with unmelted powder was found in metallographic test. The hardness of the sintered stainless steel powder is greater than the raw material. The tensile strength is less than the raw material, and it is corresponding to different scanning paths. The specimen will have different patterns of cracking. It was found that the helical scanning path specimen will have a warpage deformation at the edge of the specimen. The S-scan path specimen surface is relatively flat.

Keywords: laser sintering, sintering path, microstructure, mechanical properties

Procedia PDF Downloads 159

Authors: Zaid Haris

Abstract:

Since the beginning of time, transgender people have faced difficult circumstances, particularly in Pakistan. They have experienced discrimination, physical abuse, sexual assault, and murder in their lives. In response to their complaints, the Pakistani Supreme Court established a landmark that enables them to participate in society on an equal base. As a result, transgendered people living all around Pakistan have seen their legal, political, and cultural advocacy blossom since 2009. In order to provide and defend the human rights of Pakistan's transgender persons, this paper aims to identify and analyse the constitutional and legal framework set out there. The Supreme Court's momentous decision sparked legal reform in the nation for these rights, most notably the Transgender Persons (Protection of Rights) Act of 2017, a bill that was filed in Parliament. The implementation of the rights granted to transgender people in Pakistan, whether it relates to education, health, or any other area, requires close inspection. Additionally, for society to be accepting and inclusive, a significant and radical change in behaviour is required. This paper also includes the interviews of a few transgenders from Pakistan.

Keywords: discrimination, islam, pakistan, physical abuse, sexual assault, transgenders

Procedia PDF Downloads 125