Browse Items (11810 total)
Sort by:
-
Thermal Barrier Coating Development on Automobile Piston Material (Al-Si alloy), Numerical Analysis and Validation
This work is focused on the thermal barrier coating (TBC) development on aluminium-silicon (Al-Si) alloy casting materials, widely used as automobile components (cylinder blocks, pistons etc.). TBCs enable enhanced combustion within the chambers of diesel engines resulting in improved performance and components life. Uniform coating thickness development on complex contours of automobile pistons is a challenging task worldwide which results in varying thermal barrier characteristics across the non-uniform thickness. In consistent (in thickness) coatings are most likely to lead to uneven thermal barrier effects across the TBC thicknesses which directly affect the performance and the lubrication system of the engine. This warrants the development of stable and consistently thick coatings for ideal performance of the Low Heat rejection (LHR) engine. The present research work involved building different thicknesses (100, 125 and 150?m) of commercial 6-8%Yttria stabilized zirconia (YSZ) TBCs on 50? to 75? thick nickel aluminide (NiAl) bond coat. The influence of thickness on thermal barrier characteristics via experimentation and numerical analysis has been studied. Flat plates machined from automobile pistons were used as substrates. The coatings were characterized for thermal barrier effects for hot ceramic surface face temperatures up to 550C (by using oxy-acetylene flame to heat up the TBC surface), structural phase analysis by X-ray Diffraction (XRD) and microstructure analysis in metallographic cross section by employing Scanning Electron Microscope (SEM). An analytical investigation also was carried out to determine the approximate temperature at each interface. A code was developed to calculate the temperature drops across the coated plate and the net heat available at the coated surface using MATLAB. This is important considering the effects, small changes in temperatures will bring on the creep life on the metal. 2019 Elsevier Ltd. -
Protection offered by thermal barrier coatings to Al-Si alloys at high temperatures - A microstructural investigation
Thermal barrier coatings, with ~50 mm thick Nickel-Aluminide bond coat and ~250 mm thick Yttria-Stabilized zirconia ceramic top coats were synthesized by Air Plasma Spray coating process on flat plates machined from Al-11Si alloy diesel engine pistons. Coating process parameters and qualifications that were followed were based on previous studies made on the same substrates. The ceramic coatings were subjected to various thermal treatments such as (a) thermal shock cycling tests and (b) continuous heating in a furnace. Uncoated Al-Si samples were simultaneously subjected to the same thermal treatments and used as reference to study the protection offered by the coatings to the base metal substrates. Thermal shock cycles tests involved subjecting the coated and uncoated Al-Si plates to oxy-acetylene flame to allow the ceramic surface to be maintained at 500 C for 1000 cycles (one cycle comprised of heating for 60 s, withdrawal from flame and forced cooling in ambient air for 60 s) and similar thermal shock cycles in an electric furnace. The specimen were also heated in a furnace at 300 C for 1000 continuous hours. Stresses induced during thermal shock cycles and oxidation of bond coat-ceramic coat interface during the exposure to heat are the main reasons for the coating's failure. Details of an investigation on the microstructural changes and oxidation behaviour of the substrate and the ability of the coatings to protect the metal substrates from oxidation are presented. Microstructural studies were carried out by employing a Scanning Electron Microscope attached with Energy Dispersive X-ray spectroscopy facility. The findings were compared on (a) uncoated Al-Si alloy and (b) thermal barrier coated Al-Si alloy with a goal to understand the capability of the coatings to protect the metal from the influences of thermal treatments, at temperatures lower than the melting point of the Al-Si alloy. 2019 Elsevier Ltd. All rights reserved. -
Residual stresses analysis on thermal barrier coatingsndt tool for condition assessment
Improvement in the engine efficiency follows reduction in fuel consumption which is possible by increasing the engine combustion temperature. Coating the piston of diesel engine with a high temperature-resistant material, known as thermal barrier coating, generally 68% Y2O3 stabilized ZrO2, is a popular method to reduce the temperature it experiences in service and to increase engine efficiency. Whether bare or coated component, fabrication and different thermal expansion coefficients of the ceramic coating and piston metal cause generation of residual stresses in them. These hidden residual stresses (tensile or compressive) play a significant role in governing the failure mechanism of the different sections of the components and their important role (also developed in service) is mostly neglected in engineering practices. Residual stresses analysis of components in service may throw light on the condition of the components without destroying them. In this work, portable X-ray residual stress analyzer was used to evaluate the condition of AlSi alloys piston flat plates that were coated with 250-m-thick 68% Y2O3 stabilized ZrO2 and subjected to thermal treatments. The analysis revealed (a) residual stress-free pattern for uncoated AlSi substrate, (b) compressive residual stress at the substrate (AlSi)coating (TBC) interface and (c) tensile residual stress at the substrate (AlSi)coating (TBC) interface of a thermal shocked coated substrate. The analysis method exhibited good possibility for using this as a tool for non-destructive testing for predicting the onset of failure at the coating substrate interface, without destroying the component in service. Springer Nature Singapore Pte Ltd 2020. -
Investigation on thermal barrier effects of 8YPSZ coatings on Al-Si alloy and validation through simulation
In high temperature engineering field, protection of metal components operating at high temperatures has been a problem since the attempts to realize high efficiency aero engines in the 1940s. Researchers have been working on finding a solution for this issue and thermally insulating the surface of the base metal component with a suitable high temperature material, generally a ceramic, is one solution. The Thermal Barrier Coatings, popular worldwide as TBCs have found wide spread applications in aerospace and automobile industry after its successful application in aerospace engines in mid 1970s. In the field of aerospace, generally a super alloy will be the substrate and in automobile field this process is very much suited on aluminium casting alloys, which is the raw material for high speed diesel engine cylinder blocks and pistons. Although a good quantity of research work on TBCs have been completed in the field of aerospace, the published literature on such coatings on Aluminium castings alloys are limited. Present research aims to throw some light in this grey area by plasma spray coating Aluminium-Silicon (Al-Si) substrates with popular Yttria Partially Stabilized Zirconia as top coat and underlying nickel aluminide bond coat. Al-Si alloys are widely used in automobiles. Experiments were conducted to evaluate the temperature drop across a 250 mm thick TBC at different ceramic surface temperatures and then validating the experimental results by simulation in ANSYS. Experimental results and simulated results showed a close match, thereby validating the findings. 2019 Elsevier Ltd. All rights reserved. -
Nanosheets of nickel, cobalt and manganese triple hydroxides/oxyhydroxides as efficient electrode materials for asymmetrical supercapacitors
Transition metals play a significant role in energy storage applications mainly as electrode materials in supercapacitors. In this work, triple hydroxide/oxyhydroxide nanosheets of a nickel, cobalt and manganese (NCM) composite were electrochemically deposited on carbon cloth (CC) and used as electrode materials in supercapacitors. In a three electrode system the composite delivered a specific capacitance of 707 F g -1 at a current density of 3 A g -1 which retained its stability even at a higher current density of 50 A g -1 . An asymmetric supercapacitor (ASC) was assembled and characterized using NCM as the positive electrode, activated carbon as the negative electrode and Whatman filter paper soaked in KOH as the separator. The device operated in a working potential window of 1.75 V and it delivered a power density of 13.12 kW kg -1 and an energy density of 23.7 W h kg -1 . 2019 The Royal Society of Chemistry. -
Preprocessing Big Data using Partitioning Method for Efficient Analysis
Big data collection is the process of gathering unprocessed and unstructured data from disparate sources. As data deluge, the large volume of data collected and integrated consist missing values, outliers, and redundant records. This makes the big dataset insignificant for processing and mining knowledge. Also, it unnecessarily consumes large amount of valuable storage for storing redundant data and meaningless data. The result obtained after applying mining techniques in this insignificant data lead to wrong inferences. This makes it inevitable to preprocess data in order to store and process big dataset effectively and draw correct inferences. When data is preprocessed before analytics the storage consumption is less and computation and communication complexity is reduced. The analytics result is of high quality and the needed time for processing is considerably reduced. Preprocessing data is inevitable for applying any analytics algorithm to obtain valuable pattern. The quality of knowledge mined from large volume of big data depends on the quality of input data used for processing. The major steps in big data preprocessing include data integration from disparate sources, missing value imputation, outlier detection and treatment, and handling redundant data. The process of integration includes steps such as extraction, transformation, and loading. The data extraction step gathers useful data used for analytics and the transformation process organize the collected data in structured format suitable for analytics. The role of load process is to store transformed data into secured storage so that data can be obtained and processed effectively in future. This work provides preprocessing techniques for big data that deals with missing values and outliers and results in obtaining quality data partitions. 2023 IEEE. -
Real-World Application of Machine Learning and Deep Learning
The world today is running on the latest computer technologies and one of those is machine learning. The real life example that most of us know is speech recognition. Google Assistant is the common example for this Speech recognition. This google assistant is not only limited till 'Ok Google', but it responds to all your questions in a smart way. It can manage all your calls or can book appointments. Imagine you fell down while de-boarding a bus. So, Next time you take care so that you don't fall that is something that your brain has interpreted from your past experience. This is what exactly deep learning is, it imitates human brain works. Deep learning is sub-branch of machine learning. It is able to build all new things based on its previous experiences. Many of us have heard about driverless cars and medical diagnosis. Recently google has developed a new technology where all your cardiovascular events can be predicted by eye scan so, that doctors can get a clear view of what is inside the body of a patient. These all are developed using machine learning. It has a capability to change the human world into a complete robotic world. Anyways, it also has its own disadvantages. This article discusses about those, Scope of machine learning, its Market potential, financial growth and Current applications of machine learning. 2019 IEEE. -
Enhancing the Recognition of Hand Written Telugu Characters: Natural Language Processing and Machine Learning Approach
Handwritten character recognition has wider application in many areas including heritage documents, education, document digitalization, language processing, and assisting the visually handicapped and other related areas. The paper tries to improve the accuracy and efficiency of recognizing handwritten letters of Telugu language scripts, a difficult task for computers. Telugu is most widely spoken language in southern part of India, it has rich cultural heritage. Using the Natural Language Toolkit (NLTK), this study investigates ways to enhance recognition accuracy by analyzing handwritten content and implementing methods such as feature extraction and classification. The purpose is to use NLTK's capabilities to develop handwritten character recognition. 2024 IEEE. -
Semi automated silkworm cocoon cutting machine /
Patent Number: 202141027195, Applicant: Dr. Jyothi Thomas.
Our Invention Semi Automated Silkworm Cocoon Cutting Machine is a cocoon cutting machine with 10 cutting blades is used to separate cocoon from the pupa without killing it. The inventive device includes a main frame with vibrating hopper and a vibrating table and in between there are 10 numbers of bobbin to carry the cocoon and 10 nos. of cutting disc blades mounted on a motor at 45° to cut the cocoon. -
-
Indian catholic priests' identity, relational autonomy and attachment to god : A Narrative analysis
A thematic narrative analysis was carried to explore the 28 South Indian Roman Catholic religious priests identity, relational autonomy and attachment to God. Fourteen participants were selected from the structured priestly ministry settings newlinenamely education ministry and, another 14 participants from the semi-structured newlinepriestly ministry settings namely parish and priestly formation ministry settings. The newlinequalitative data collected through the interviews were analyzed through the narrative thematic analysis method. The thematic narrative analysis found five major themes, influence on the priestly identity, value-oriented life, purpose in life, priestly celibacy and challenges in the priestly ministry and 46 subthemes for the participants priestly identity narratives. For relational autonomy, the study found five major themes, impactful childhood, the influence of priestly formation, nterpersonal relationships, relationship with the person in authority and decision making and 42 subthemes. For attachment God, it found six major themes, God as an attachment figure, seeking and maintaining proximity to God, God as a haven of safety, God as a secure base, newlineperceiving God as stronger and wiser, and individual differences in attachment to newlineGod, and 24 sub-themes. The study results revealed strong support for the newlinecorrespondence pathway, as the majority of the participants had narratives of newlinecorrespondence between the attachment to their parents and their attachment to God. newlineIt also found evidence for the theme of compensation in three participants narratives. The qualitative comparison between the groups found that for 19 sub-themes for priestly identity, 20 sub-themes for relational autonomy and 13 sub-themes for newlineattachment to God, the priests from the structured ministry settings differed from the priests from the semi-structured ministry settings. -
Indian catholic priests' identity, relational autonomy and attachment to god: A narrative analysis
A thematic narrative analysis was carried to explore the 28 South Indian Roman Catholic religious priests’ identity, relational autonomy and attachment to God. Fourteen participants were selected from the structured priestly ministry settings namely education ministry and, another 14 participants from the semi-structured priestly ministry settings namely parish and priestly formation ministry settings. The qualitative data collected through the interviews were analyzed through the narrative thematic analysis method. The thematic narrative analysis found five major themes, influence on the priestly identity, value-oriented life, purpose in life, priestly celibacy and challenges in the priestly ministry and 46 subthemes for the participants’ priestly identity narratives. For relational autonomy, the study found five major themes, impactful childhood, the influence of priestly formation, interpersonal relationships, relationship with the person in authority and decision making and 42 subthemes. For attachment God, it found six major themes, God as an attachment figure, seeking and maintaining proximity to God, God as a haven of safety, God as a secure base, perceiving God as stronger and wiser, and individual differences in attachment to God, and 24 sub-themes. The study results revealed strong support for the correspondence pathway, as the majority of the participants had narratives of correspondence between the attachment to their parents and their attachment to God. It also found evidence for the theme of compensation in three participants’ narratives. -
Preventing Data Leakage and Traffic Optimization in Software-Defined Programmable Networks
The first widely used communication infrastructure was the telephone network, often known as a connection-oriented or circuit-switched network. While making a phone call, these networks will first set up a connection, and then tear it down after the call has ended. The connection made during the call would not be used again. Thus, connectionless or packet-switched networks have been introduced, with an aim to send voice signals as data packets. When compared to conventional network architecture, SDN's separation of the data plane and control plane of networking devices makes the management of these devices directly programmable via a centralised controller. It uses a MAS-based distributed architecture to categorise network flows, and it's called the Traffic Classification Module. Each host or server's high-priority application traffic is isolated via Deep Packet Inspection (DPI). The time consumed for a packet to travel from one endpoint to another is referred to as the average packet delay, whereas the controller's reaction time is twice the average packet delay. Few works existed that utilised routing strategies to decrease the typical packet delay in SDN. To reduce the controller's response time, Software-Defined Networks (SDNs) need a routing algorithm that reduces the average packet delay. Each of the proposed modules and the whole combined SDN-MASTE framework were put through their paces in a series of experiments and emulation-based tests to see how well they performed. 2023 IEEE. -
Integration of blockchain to IoT: Possibilities and pitfalls
[No abstract available] -
Did the Economic Reforms Change the Macroeconomic Drivers of the Indian Economy in the Post-Reform Era? An ARDL Bounds Test Approach
Purpose: The purpose of this study is to investigate the macroeconomic forces that have been driving the Indian economy during both the pre-reform and post-reform eras, that is, from 1950-1951 to 1990-1991 and from 1991-1992 to 2022-2023 respectively. Problem: The Indian economy underwent significant economic and financial sector reforms in 1991-92, with the goal of reviving its stagnant growth. These reforms are intended to spur the economic growth of India. What were the main forces behind the Indian economy before and after the reforms? Is the research question. The goal of the current study is to determine if the economic reforms shifted or maintained the pre-reform eras driving forces for the Indian economy in the post-reform era. Design/Methodology/Approach: The gross domestic product (GDP), the gross domestic savings (GDS), the private consumption expenditure (PFCE), the government final consumption expenditure (GFCE), the inflation rate, the exchange rate, the exports, the imports, the internal and external borrowings of the government, personal remittances, foreign direct investment (FDI), and foreign portfolio investments (FPI) are all taken into consideration in order to fill the research gap that has been identified as a result of the comprehensive review of the literature. Following an analysis of the selected variables' fundamental characteristics, an econometric model is developed using the Autoregressive Distributed Lag (ARDL) Bounds Test Model. Findings: There is no evidence of long-run causation and association between the variables, but the findings of the ARDL Bounds Test showed that in the pre-reform period, PFCE is the major driver of the GDP in the short-run, with strong support from imports. However, since the reform, PFCE, GDS, and Exports are the primary short-and long-term contributors to GDP. Practical Implication: These findings indicate that India's macroeconomic system is shifting. The Indian economy has undergone a dramatic shift, moving away from a reliance on imports and toward one that is consumer-driven and export-driven. As savings and consumer expenditures are the main drivers of the Indian economys growth in the post-reform era, policies should be designed to increase savings and consumption as well as increase exports. 2023, ASERS Publishing House. All rights reserved. -
Image and signal processing in the underwater environment
To handle submerged action recognition, researchers must first understand the fundamental principles of photonic crystals mostly in the liquid phase. Deterioration effects are produced by the mediums physical attributes, which are not present in typical pictures captured in the air because light is increasingly reduced as it passes through water, submarine pictures are characterized by low readability. As a consequence, the sceneries are poorly contrasting and murky. Its vision capability is limited to approximately twenty meters in clear blue water and five meters or less in muddy water due to light dispersion. Absorbing (the removal of incident light) and dispersion are the two factors that produce light degradation. So the actual quality of submersible digital imaging is influenced by the destructive interference processes of light in water. Longitudinal scattered (haphazardly diverted light traveling from objects to the cameras) causes picture details to be blurred. 2021, SciTechnol, All Rights Reserved. -
Ethnic Food: The Food Way Forward
In the context of food security, two things are significant. To ensure availability, affordability and accessibility of adequate food to people throughout the country. Also, to promote entrepreneurship for sustainable food production and supply. This paper highlights differences between food security and food insecurity. The global population in 2050 is predicted at 9 billion in which case the output must double considering the dwindling and degrading resources. This may be a challenge for agronomists and policy-makers. Considering that food security must be achieved at individual, household, district, national and global levels, India may need an Integrated Farming System (IFS) to take agriculture further. There are numerous challenges besides the environment that must be considered for this. It is important to ensure that the dignity of the farmer is not compromised while strategizing food security. Currently, private-public partnerships are being introduced in some places as a potential model. However, all stakeholders in food security have their task cut out (1). This paper is a review of existing literature to understand the level of information we have documented. It tries to highlight ways in which consumption of ethnic food could be a way forward in terms of food security and sustainability. The Electrochemical Society -
One-pot hydrothermal synthesis of 3D garland BiOI, spherical ZnO, and CNFs onto Ni foam: Supercapacitor performance with enhanced electrochemical properties
This study reported one-pot hydrothermal synthesis of 3D garland BiOI, spherical ZnO, and carbon nanofibers (CNFs) onto Ni foam substrate with improved supercapacitor performance and enhanced electrochemical properties. The synthesized nanocomposites exhibited high specific capacitance (SC) of 1073 g?1 at a current density of 1 A/g and excellent cycling stability with 88.6% retention of original capacity after 5000 cycles in 2M KOH aqueous solution. The findings highlight the potential of 3D materials for use as electrode materials in advanced supercapacitor applications due to their high energy storage capabilities. 2024 Elsevier Ltd -
Contextual Recommendation System: A Revolutionary Approach Using Hadoop, Spark, NLP and LLMs
This study presents a novel framework for contextual recommendations on platforms like Wikipedia, integrating Hadoop, Spark, NLP, and LLMs. Leveraging these technologies, the framework aims to enhance user experiences by delivering personalized article suggestions aligned with their current interests. Through scalable data processing, advanced NLP techniques, and LLM-powered semantic understanding, the framework offers a transformative approach to recommendation systems, promising to revolutionize knowledge exploration on digital platforms. 2024 IEEE. -
Child Mental Health in the Milieu of Online Education
The aim of this chapter is to examine the impact of online education on mental health of children, and explore methods to improve the same. With the advent of COVID-19 pandemic, major overhauls were made in day-to-day life including work, home, and education. Shift to online mode of instruction became the primary, if not the only, channel of education. This drastic shift has led to issues like limited social interaction, learning gaps due to insufficient in-person interaction, excessive screen time on devices, and decreased physical activity, which can impact mental health of children. This chapter will explore the impact of online learning on the mental health of children from both mental ill-health and well-being perspectives, the role of parents, teachers, and educational systems, and challenges and opportunities presented by the situation. Further to this, the ways to safeguard and improve mental health of children in the milieu of online education will be discussed. The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2022.