Veerraju Gampala, Praful Vijay Nandankar, M. Kathiravan, S. Karunakaran, Arun Reddy Nalla and Ranjith Reddy Gaddam
The purpose of this paper is to analyze and build a deep learning model that can furnish statistics of COVID-19 and is able to forecast pandemic outbreak using Kaggle open…
Abstract
Purpose
The purpose of this paper is to analyze and build a deep learning model that can furnish statistics of COVID-19 and is able to forecast pandemic outbreak using Kaggle open research COVID-19 data set. As COVID-19 has an up-to-date data collection from the government, deep learning techniques can be used to predict future outbreak of coronavirus. The existing long short-term memory (LSTM) model is fine-tuned to forecast the outbreak of COVID-19 with better accuracy, and an empirical data exploration with advanced picturing has been made to comprehend the outbreak of coronavirus.
Design/methodology/approach
This research work presents a fine-tuned LSTM deep learning model using three hidden layers, 200 LSTM unit cells, one activation function ReLu, Adam optimizer, loss function is mean square error, the number of epochs 200 and finally one dense layer to predict one value each time.
Findings
LSTM is found to be more effective in forecasting future predictions. Hence, fine-tuned LSTM model predicts accurate results when applied to COVID-19 data set.
Originality/value
The fine-tuned LSTM model is developed and tested for the first time on COVID-19 data set to forecast outbreak of pandemic according to the authors’ knowledge.
Details
Keywords
Karunakaran C.S. and Ashok Babu J.
The purpose of this study is to analyze the effect of human factor training in aircraft maintenance accident mitigation and aircraft safety in post COVID-19 aviation scenarios…
Abstract
Purpose
The purpose of this study is to analyze the effect of human factor training in aircraft maintenance accident mitigation and aircraft safety in post COVID-19 aviation scenarios. The cause of aircraft accidents and details of three decades of selective aircraft maintenance accidents are analyzed to arrive to the significant aviation safety factor. The effect of COVID-19 pandemic and related technological applications to maintain high standards of safety and their applications in aircraft maintenance with respect to the view of human factors are discussed in details.
Design/methodology/approach
This paper details the overview of the human errors, error mitigation and need of human factor applications in aircraft maintenance industry for safe air travel. The criticality of aircraft maintenance in keeping aircraft in airworthy condition to provide safe air transportation without delay and to support airline economy is discussed in this study.
Findings
The cause of aircraft accidents and details of three decades of selective aircraft maintenance accidents are analyzed to arrive to the significant aviation safety factor. The effect of COVID-19 pandemic and related technological applications to maintain high standards of safety and their applications in aircraft maintenance with respect to the view of human factors are discussed in details. The route of error mitigation and need of high standard technological training with human factor knowledge, to aircraft maintenance students are analyzed in detail with the opportunity of percentages of error reduction.
Originality/value
This study bridges, gained knowledge for aircraft maintenance error mitigation, current accident rates and future training needs for safest air travel through high standard quality maintenance in aircraft and its systems.
Details
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Suryakumar Simhambhatla and K.P. Karunakaran
– This paper aims to develop build strategies for rapid manufacturing of components of varying complexity with the help of illustration.
Abstract
Purpose
This paper aims to develop build strategies for rapid manufacturing of components of varying complexity with the help of illustration.
Design/methodology/approach
The build strategies are developed using a hybrid layered manufacturing (HLM) setup. HLM, an automatic layered manufacturing process for metallic objects, combines the best features of two well-known and economical processes, viz., arc weld-deposition and milling. Depending on the geometric complexity of the object, the deposition and/or finish machining may involve fixed (3-axis) or variable axis (5-axis) kinematics.
Findings
Fixed axis (3-axis) kinematics is sufficient to produce components free of undercuts and overhanging features. Manufacture of components with undercuts can be categorized into three methods, viz., those that exploit the inherent overhanging ability, those that involve blinding of the undercuts in the material deposition stage and those that involve variable axis kinematics for aligning the overhang with the deposition direction.
Research limitations/implications
Although developed using the HLM setup, these generic concepts can be used in a variety of metal deposition processes.
Originality/value
This paper describes the methodology for realizing undercut features of varying complexity and also chalks out the procedure for their manufacture with the help of case studies for each approach.
Details
Keywords
Pieter Johannes Theron Conradie, Dimitri Dimitrov, Gert Adriaan Oosthuizen, Philip Hugo and Mike Saxer
The purpose of this paper is to investigate the combination of selective laser melting (SLM) and 5-axis CNC milling to produce parts from titanium powder. The aim is to achieve a…
Abstract
Purpose
The purpose of this paper is to investigate the combination of selective laser melting (SLM) and 5-axis CNC milling to produce parts from titanium powder. The aim is to achieve a more resource-efficient manufacturing process by reducing material wastage and machining time, while adhering to quality requirements.
Design/methodology/approach
A benchmark titanium aerospace component is manufactured with two different approaches using subtractive and additive manufacturing technologies. The first component is produced from a solid billet using only 5-axis CNC milling. The second component is grown from powder using SLM to produce a net-shaped part of which the final shape and part accuracy are achieved through 5-axis CNC milling. The potential saving of material and machining time of the process combination is evaluated by comparing it to the conventional purely CNC approach. The form accuracy, surface finish, mechanical properties and tool wear for the two processes are also compared.
Findings
The results show that the process combination can be used to produce Ti components that adhere to aerospace standards. With the process combination, a material saving of 87 per cent was achieved along with a reduction of 21 per cent in machining time. Further improvements are possible using optimized SLM build and machining strategies.
Originality/value
This paper presents the results of a resource efficiency assessment on the combination of SLM and 5-axis CNC milling for the titanium alloy, Ti6Al4V. It is expected that this process combination can make a significant contribution towards reducing material wastage and machining time for aerospace applications.
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Keywords
Pushkar Prakash Kamble, Subodh Chavan, Rajendra Hodgir, Gopal Gote and K.P. Karunakaran
Multi-jet deposition of the materials is a matured technology used for graphic printing and 3 D printing for a wide range of materials. The multi-jet technology is fine-tuned for…
Abstract
Purpose
Multi-jet deposition of the materials is a matured technology used for graphic printing and 3 D printing for a wide range of materials. The multi-jet technology is fine-tuned for liquids with a specific range of viscosity and surface tension. However, the use of multi-jet for low viscosity fluids like water is not very popular. This paper aims to demonstrate the technique, particularly for the water-ice 3 D printing. 3 D printed ice parts can be used as patterns for investment casting, templates for microfluidic channel fabrication, support material for polymer 3 D printing, etc.
Design/methodology/approach
Multi-jet ice 3 D printing is a novel technique for producing ice parts by selective deposition and freezing water layers. The paper confers the design, embodiment and integration of various subsystems of multi-jet ice 3 D printer. The outcomes of the machine trials are reported as case studies with elaborate details.
Findings
The prismatic geometries are realized by ice 3 D printing. The accuracy of 0.1 mm is found in the build direction. The part height tends to increase due to volumetric expansion during the phase change.
Originality/value
The present paper gives a novel architecture of the ice 3 D printer that produces the ice parts with good accuracy. The potential applications of the process are deliberated in this paper.
Details
Keywords
Sajan Kapil, Prathamesh Joshi, Hari Vithasth Yagani, Dhirendra Rana, Pravin Milind Kulkarni, Ranjeet Kumar and K.P. Karunakaran
In additive manufacturing (AM) process, the physical properties of the products made by fractal toolpaths are better as compared to those made by conventional toolpaths. Also, it…
Abstract
Purpose
In additive manufacturing (AM) process, the physical properties of the products made by fractal toolpaths are better as compared to those made by conventional toolpaths. Also, it is desirable to minimize the number of tool retractions. The purpose of this study is to describe three different methods to generate fractal-based computer numerical control (CNC) toolpath for area filling of a closed curve with minimum or zero tool retractions.
Design/methodology/approach
This work describes three different methods to generate fractal-based CNC toolpath for area filling of a closed curve with minimum or zero tool retractions. In the first method, a large fractal square is placed over the outer boundary and then rest of the unwanted curve is trimmed out. To reduce the number of retractions, ends of the trimmed toolpath are connected in such a way that overlapping within the existing toolpath is avoided. In the second method, the trimming of the fractal is similar to the first method but the ends of trimmed toolpath are connected such that the overlapping is found at the boundaries only. The toolpath in the third method is a combination of fractal and zigzag curves. This toolpath is capable of filling a given connected area in a single pass without any tool retraction and toolpath overlap within a tolerance value equal to stepover of the toolpath.
Findings
The generated toolpath has several applications in AM and constant Z-height surface finishing. Experiments have been performed to verify the toolpath by depositing material by hybrid layered manufacturing process.
Research limitations/implications
Third toolpath method is suitable for the hybrid layered manufacturing process only because the toolpath overlapping tolerance may not be enough for other AM processes.
Originality/value
Development of a CNC toolpath for AM specifically hybrid layered manufacturing which can completely fill any arbitrary connected area in single pass while maintaining a constant stepover.
Details
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Yogesh Patil, Milind Akarte, K. P. Karunakaran, Ashik Kumar Patel, Yash G. Mittal, Gopal Dnyanba Gote, Avinash Kumar Mehta, Ronald Ely and Jitendra Shinde
Integrating additive manufacturing (AM) tools in traditional mold-making provides complex yet affordable sand molds and cores. AM processes such as selective laser sintering (SLS…
Abstract
Purpose
Integrating additive manufacturing (AM) tools in traditional mold-making provides complex yet affordable sand molds and cores. AM processes such as selective laser sintering (SLS) and Binder jetting three-dimensional printing (BJ3DP) are widely used for patternless sand mold and core production. This study aims to perform an in-depth literature review to understand the current status, determine research gaps and propose future research directions. In addition, obtain valuable insights into authors, organizations, countries, keywords, documents, sources and cited references, sources and authors.
Design/methodology/approach
This study followed the systematic literature review (SLR) to gather relevant rapid sand casting (RSC) documents via Scopus, Web of Science and EBSCO databases. Furthermore, bibliometrics was performed via the Visualization of Similarities (VOSviewer) software.
Findings
An evaluation of 116 documents focused primarily on commercial AM setups and process optimization of the SLS. Process optimization studies the effects of AM processes, their input parameters, scanning approaches, sand types and the integration of computer-aided design in AM on the properties of sample. The authors performed detailed bibliometrics of 80 out of 120 documents via VOSviewer software.
Research limitations/implications
This review focuses primarily on the SLS AM process.
Originality/value
A SLR and bibliometrics using VOSviewer software for patternless sand mold and core production via the AM process.
Details
Keywords
Somashekara M. Adinarayanappa and Suryakumar Simhambhatla
Twin-wire welding-based additive manufacturing (TWAM) is a unique process which uses gas metal arc welding (GMAW)-based twin-wire weld-deposition to create functionally gradient…
Abstract
Purpose
Twin-wire welding-based additive manufacturing (TWAM) is a unique process which uses gas metal arc welding (GMAW)-based twin-wire weld-deposition to create functionally gradient materials (FGMs). Presented study aims to focus on creating metallic objects with a hardness gradient using GMAW of twin-wire weld deposition setup.
Design/methodology/approach
By using dissimilar filler wires in twin-wire weld-deposition, it is possible to create metallic objects with varying hardness. This is made possible by individually controlling the proportion of each filler wire used. ER70S-6 and ER110S-G are the two filler wires used for the study; the former has lower hardness than the latter. In the current study, methodology and various experiments carried out to identify the suitable process parameters at a given location for a desired variation of hardness have been presented. A predictive model for obtaining the wire speed of the filler wires required for a desired value of hardness was also created. Subsequently, sample parts with gradient in various directions have been fabricated.
Findings
For dissimilar twin-wire weld-deposition used here, it is observed that the resultant hardness is in the volumetric proportion of the hardness of the individual filler wires. This aids the fabrication of FGMs using arc based weld-deposition with localized control of hardness, achieved through the control of the ratio of wire speeds of the individual filler wires. Four sample parts were fabricated to demonstrate the concept of realizing FGMs through TWAM. The fabricated parts showed good match with the desired hardness variation.
Research limitations/implications
This paper successfully presents the capability of TWAM for creating gradient metallic objects with varying hardness. Although developed using ER70S-6 and ER110S-G filler wire combination, the methodology can be extended for other filler wire combinations too for creating FGMs
Originality/value
GMAW-based twin-wire welding for additive manufacturing is a novel process which uses dissimilar filler wires for creating FGMs. This paper describes methodology of the same followed by illustration of parts created with bi-directional hardness gradient.
Details
Keywords
Eslam Taha, Mostafa Attia Mohie, Mahmoud Sayed Korany, Naglaa Aly, Alaa Ropy and Mosaad Negem
This study aims to investigate profoundly the protection of oil painting from deterioration using molybdenum trisulphide quantum dots (MoS3 QDs) against microbe, dirt accumulation…
Abstract
Purpose
This study aims to investigate profoundly the protection of oil painting from deterioration using molybdenum trisulphide quantum dots (MoS3 QDs) against microbe, dirt accumulation and ultraviolet (UV) degradation.
Design/methodology/approach
The protection of painting against different deterioration factors necessitates the sustainable methods and advanced techniques. Scanning electron microscopy and transmission electron microscopy have been used to investigate the morphological structure of the painting and MoS3 QDs, respectively, and optical microscopy was used to examine antibacterial activity of MoS3 QDs towards different types of bacteria. To investigate the protection of painting against deterioration, the Fourier transform IR spectroscopy (FTIR) was used to investigate the paintings left in open air for a year. Chemical composition and crystal structure of MoS3 QDs have been studied using X-ray diffraction and X-ray photoelectron spectroscopy analysis, respectively.
Findings
The addition of MoS3 nanoparticles into painted coatings enhances the durability of linseed oil-based paintings toward UV ageing regarding the change in colour which confirmed by FTIR analysis. The protection of oil painting opposed to various deterioration factors was developed by involving of MoS3 QDs in the coating of the painting. Antibacterial effect of MoS3 QDs was tested against different types of bacteria such as Pseudomonas aeruginosa confirming that the MoS3 QDs involved in the coatings of oil paintings produces a high protection layer for the paintings against several microbial attacks. In addition, coatings containing MoS3 QDs reduce the accumulation of dirt on oil paintings when subjected to open air for a year.
Originality/value
The novel MoS3 QDs was used to form a protective and transparent coating layer for the oil painting to overcome the deterioration, displays the promising protection and can be applied for different oil paintings.
Details
Keywords
K.P. Karunakaran, Alain Bernard, S. Suryakumar, Lucas Dembinski and Georges Taillandier
The purpose of this paper is to review additive and/or subtractive manufacturing methods for metallic objects and their gradual evolution from prototyping tools to rapid…
Abstract
Purpose
The purpose of this paper is to review additive and/or subtractive manufacturing methods for metallic objects and their gradual evolution from prototyping tools to rapid manufacture of actual parts.
Design/methodology/approach
Various existing rapid manufacturing (RM) methods have been classified into six groups, namely, CNC machining laminated manufacturing, powder‐bed technologies, deposition technologies, hybrid technologies and rapid casting technologies and discussed in detail. The RM methods have been further classified, based on criteria such as material, raw material form, energy source, etc. The process capabilities springing from these classifications are captured in the form of a table, which acts as a database.
Findings
Due to the approximation in RM in exchange for total automation, a variety of multi‐faceted and hybrid approaches has to be adopted. This study helps in choosing the appropriate RM process among these myriad technologies.
Originality/value
This review facilitates identification of appropriate RM process for a given situation and sets the framework for design for RM.