Dr. SungCheal Moon
Department of Polymer Engineering, Industrial Technology Support Division, Korea Institute of Materials Science (KIMS), Republic of Korea.

ISBN 978-93-90888-66-5 (Print)
ISBN 978-93-90888-71-9 (eBook)
DOI: 10.9734/bpi/aaer/v7

This book covers key areas of engineering research. The contributions by the authors include   multi-level inverter, phase disposition, total harmonic distortion, Unified power quality conditioner, dynamic voltage restorer, distribution static, total harmonic distortion, competitive agglomeration, fuzzy c-means, fuzzy learning vector quantization, railway signalling, code refactoring impact, software quality, software component, automatic code transformation, downdraft gasifier design, specific gasification rate, gasifier efficiency, throatless gasifier, equivalence ratio, sustainable energy, social infrastructure, solar energy, bio-energy, renewable energy business incubators, oil-in-water emulsion, polymeric films, suspended loads, vibration, dynamic model, elastic beam, celiac disease, sensors, nanofibers, nanorods, base pressure, nozzle pressure ratio, passive control, two-phase ejector, expansion device, air conditioners, coefficient of performance, construction delays, data collection integration system. This book contains various materials suitable for students, researchers and academicians in the field of engineering research.


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Phase Disposition PWM Based Multi Level Inverter with Reduced Number of Switches

V. Karthikeyan, V. Jamuna, I. William Christopher

Advanced Aspects of Engineering Research Vol. 7, 6 May 2021, Page 1-15

This chapter investigates and analyses the phase disposition pulse width modulation (PDPWM) based Reduced Switch Reverse Voltage (RSRV) multi level inverter. This inverter has been designed with lesser number of components. Enhancement of output power quality using PDPWM is discussed with respect to the amplitude and frequency modulation index values. This PDPWM based 9-level inverter with reduced components and odd valued frequency modulation index value, produces better harmonic spectrum. All the lower order harmonics are well within the limit defined by the IEEE-519 standard. The simulation model of PDPWM based asymmetrical 9-level inverter with reduced number of components is built to validate its operation and the results are presented. This inverter requires lesser number of components when it is used for higher number of output levels.

This paper presents the operation of unified power quality conditioner (UPQC) as a universal active power conditioning device to mitigate both current as well as voltage distortions at a distribution end of power system network. The UPQC is designed by combining a series active power filter (DVR) and shunt active power filter (DSTATCOM) which shares a common DC link capacitor. Series compensator which is meant for voltage restoring is controlled by a fuzzy logic controller. Shunt compensator’s operation is controlled by extracting d axis and q axis current from load current and DC link voltage is maintained through a fuzzy logic controller. The performance of UPQC mainly depends upon how quickly and accurately compensation signals are derived. The steady state and dynamic operation of control circuit in different load current and/or utility voltages conditions is studied through simulation results. The presented method has acceptable dynamic response with a very simple configuration of control circuit. The designed UPQC is tested with an induction motor load. It is able to mitigate voltage sag/ swell, reactive power compensation, voltage fluctuations, harmonic elimination etc. under these load conditions. UPQC mitigates the voltage and current based distortion simultaneously as well as independently. The proposed system and controller is validated using MATLAB/simulink. The simulation results express a low THD and a perfect compensation.

The proposed work was aimed to evaluate the hybridization of fuzzy C- means and competitive agglomeration for image segmentation. It is fuzzy clustering-based vector quantization algorithm. The method of segmenting a digital image into multiple segments is known as image segmentation. For segmentation, various methodologies based on standard techniques such as region rising, threshold technique, and watershed transform have been proposed. Because of the drawbacks of these approaches, segmentation based on clustering techniques has emerged.  The central idea behind data clustering is that each cluster is represented by its centroid. In addition, the similarity of the input vectors to the centroid is used to represent each cluster. Clustering approaches are divided into two categories: parametric and nonparametric. Finding natural groupings in a dataset using a Euclidean distance between samples is a non-parametric technique. K-means, hierarchical, and spectral clustering are examples of non-parametric clustering. The lack of robustness to image noise is one of these methods' drawbacks. As a result, in image clustering and segmentation, a fuzzy segmentation technique has been commonly used. The most challenging aspect of fuzzy c-means is determining the number of clusters and choosing an objective function. As a result, we use a fuzzy clustering-based vector quantization algorithm. This algorithm makes use of a specialised objective function that combines fuzzy c-means and a competitive agglomeration term. This algorithm is fast, and the reconstructed images are of good quality.

The cab signaling is inevitable for fast trains. And search towards cab signaling is about for more than a century. This chapter is about wireless cab signaling which is economic and reliable.

The current method of signalling in Indian railways is through traditional land post light signals controlled from the station, and the light signals regulate train operation. It is often difficult to drive the train at a steady pace due to poor visibility caused by climatic conditions [mist and heavy rain], fast blind turns, up and downs, and blinding sunshine, and it is necessary to apply brakes, which causes pain and wastes energy and time. We can provide cab signals to the loco pilot instantly to improve the output of the train service without any interruption due to the above cause. With the aid of traditional land post light signal control, I present a method for providing cab light signal by electromagnetic waves (EMW). To improve the efficiency of the Indian railway signalling system, the proposed system is a preliminary implementation of cab signalling that is linked and combined with the existing automatic block signalling system.

Analysis of Code Refactoring Impact on Software Quality: A Scientific Explanation

Amandeep Kaur, Manpreet Kaur

Advanced Aspects of Engineering Research Vol. 7, 6 May 2021, Page 43-52

Code refactoring is a “Technique used for restructuring an existing source code, improving its internal structure without changing its external behaviour”. It is the process of changing a source code in such a way that it does not alter the external behaviour of the code yet improves its internal structure. It is a way to clean up code that minimizes the chances of introducing bugs. Refactoring is a change made to the internal structure of a software component to make it easier to understand and cheaper to modify, without changing the observable behaviour of that software component. Bad smells indicate that there is something wrong in the code that have to refactor. There are different tools that are available to identify and remove these bad smells. It is a technique that change our source code in a more readable and maintainable form by removing the bad smells from the code. Refactoring is used to improve the quality of software by reducing the complexity. In this paper bad smells are found and perform the refactoring based on these bad smell and then find the complexity of program and compare with initial complexity. The complexity of our project is reduced after apply the refactoring and improve the quality of our project. This paper shows that when refactoring is performed the complexity of software decrease and easily understandable.

Design of Lab-scale Downdraft Gasifier for Biomass Gasification: A Comprehensive Study

G. Suresh Kumar, AVSSKS Gupta, M. Viswanadham

Advanced Aspects of Engineering Research Vol. 7, 6 May 2021, Page 53-63

Biomass gasification is a cost effective, efficient and eco-friendly source of alternate energy. The gasification efficiency depends on several parameters like equivalence ratio, gasification agent, gasifier configuration, etc. Downdraft gasifier is a most suitable gasifier for biomass gasification due to inherent advantages like feedstock flexibility, better process control, low tar formation, and simple construction. Specific gasification rate (SGR), which determines the gasifier configuration and performance is an assumed value. The aim of this paper is to conduct a comparative study of different configurations and design a 5kW lab scale throatless biomass gasifier using analytical approach. The overview of gasification plant with various functional units and their purpose is also explained.

Recent Developments of Sustainable Energy: The Key to a Stable Nigeria

Kalu Uduma, Tomasz Arciszewski

Advanced Aspects of Engineering Research Vol. 7, 6 May 2021, Page 64-75

This paper proposes the use of sustainable energy systems based on solar and biomass technologies to provide solutions to utility challenges in Nigeria and acute water shortage both in rural and urban areas of that country. The paper highlights the paradoxes of oil-rich Nigeria and the stark reality of social infrastructure deprivations in that country. Perennial power outages over many years have translated to the absence of or poorly-developed basic social infrastructures in Nigeria. The consequences of this lack have been an increase in abject poverty in rural and urban communities as well as the erosion of social order and threats to citizen and their property. This paper proposes the adaptation of two emerging technologies for building sustainable energy systems and the development of decentralized and sustainable energy sources as catalyst for much-needed social infrastructure development through the creation of Renewable Energy Business Incubators, creative lending strategies, NGO partnerships and shifting energy-distribution responsibilities. These changes will stimulate grassroots economies in the country, develop large quantities of much needed clean water, maintain acceptable standards of sanitation and improve the health and wellbeing of Nigerian communities. The proposed strategies are specific to the Nigerian context; however, the authors suggest that the same or similar strategies may provide energy and social infrastructure development solutions to other developing countries as well.

The economic and social opportunities that sustainable energy systems can bring are significant attractions for various private and federal organizations in Nigeria to invest aggressively in the new systems.

The Ability of Different Lignins to Stabilize the Oil-in-water Emulsion

Galia Shulga, Sandra Livcha, Brigita Neiberte, Anrijs Verovkins, Sanita Vitolina, Elina Zhilinska

Advanced Aspects of Engineering Research Vol. 7, 6 May 2021, Page 76-85

The ability of aspen soda and wheat straw soda lignin to stabilize the “rapeseed oil-in-water” (O/W) emulsion, depending on the pH value and concentration of the applied water solutions as well as on the lignin chemical composition and molecular mass, and the sizes and zeta potential of lignin particles was studied. It was shown that the O/W emulsion stabilized with the alkaline water solutions of wheat straw lignin demonstrated the highest stability in alkaline medium, while the ability of aspen soda lignin to prevent the coalescence of oil droplets manifested itself in a whole range of the studied pH values. With decreasing pH values of the wheat straw lignin water solution, the drop in the separation volume of the O/W emulsion was insignificant with the exception for the lignin enhanced concentrations in acidic medium. The aggregative stability of the O/W emulsion, which was stabilized with aspen soda lignin, increased with decreasing pH values and increasing lignin content in the emulsion. The findings indicated that the stabilization of the O/W emulsion with the alkaline lignin solutions proceeded via the electrostatic stabilization mechanism, while in the neutral and acidic medium, this mechanism was more complicated, with a growing role of the ability of lignin to form interfacial polymeric films at the liquid/liquid interface. The comparison of the stability of the O/W emulsion showed that aspen soda lignin was a better stabilizer of the O/W emulsion than wheat straw lignin.

In this Chapter we analyze the dynamics of mechanical systems with suspended loads, such as bridge cranes, monorail hoists, mining machinery, etc. The considered mechanical system is composed of a load, twice elastically suspended from an elastic beam via another load. The goal is to determine the vibrations of the mechanical system with suspended loads. Two dynamical models which respect the kinetic energy of the elastic ropes are built for the system and their corresponding differential equations of motion are obtained. The vibration of the mechanical system is described by a coupled system of two ordinary and n(n=1,2,...) partial differential equations. The nonlinear restoring forces are linearized via the method of equivalent linearization and an analytical solution is obtained for the differential equations of both dynamical models simultaneously, using general initial conditions. The constants of integration are determined analytically for a specific instance of the initial conditions, which reflects an important practical case. The mechanical system is simulated numerically with initial conditions corresponding to the typical regimes of operation of real systems with suspended loads.

There is still a great trend towards sensors, whether they are gas sensors, biosensors or chemical sensors. If the gas sensors are connected with biosensor, this will result a great sensors.

The manufacture of sensors for human gases can give the important reasons for happening of the disease. Celiac disease is a disease that causes many problems for many people who suffer from it. The success in the manufacture of sensors predicts the severity and difficulty of inflammation by the rate of sensitivity and the amount of gases and type. We can be linked to what he eats and his output of the gases then can give him the right prevention for this disease and how to treat it. If the diagnosis is accurate to what the reasons leads the inflammation and connect it with what the food that leads to same reason, also. The better of devices to detect the disease are nanofibers, nanorods and nanotubes because it has a very high aria to volume ratio.

I hope that this paper will receive a great deal of attention towards this work and try to save a lot of those suffering from this annoying inflammation.

Static Cylinder as a Base Pressure Controller in Supersonic Regime

Mohammed Asadullah, S. A. Khan, Waqar Asrar, E. Sulaeman, Syed Azam Pasha Quadri

Advanced Aspects of Engineering Research Vol. 7, 6 May 2021, Page 111-122

An experimental study for over expanded, perfectly-expanded and under-expanded supersonic jets at Mach 2 is presented to study the effectiveness of a static cylinder to reduce base drag. A static cylinder of diameter 2 mm located at 2 mm from the sidewall of a square duct and 8 mm from the converging-diverging square nozzle exit in the base region is installed as a passive control device. Base pressures in the wake flow after a sudden expansion of jets into a square nozzle have been measured. The length-width ratio of the duct is 10. The jets were operated at different nozzle pressure ratios in the range from 2 to 9. The flow field in the square duct was also observed for all cases. The static cylinder as a passive controller was found to reduce the base drag as high as 59 percent at NPR = 9 and 14 percent at NPR = 6. The base pressure depends on Mach number, area ratio, length to width ratio, and nozzle pressure ratio. When the flow from the nozzle is over expanded, the static control is ineffective till NPR is 6. The level of expansion plays a vital role. The flow flux in the square duct remains almost identical with and without control for most of the cases. However, at higher NPRs namely 6, 7.8, and 9 the control results in an increase as well as a decrease in the wall pressure along the duct. Passive control of the base flow is effective for higher NPRs. The flow field for higher NPR is dominated by the shock waves. Further, this phenomenon is visualized using a shadowgraph.

Effect of Rotating Cylinder at Variable Location to Control Base Flows at Mach 2

Mohammed Asadullah, S. A. Khan, Waqar Asrar, E. Sulaeman, Syed Azam Pasha Quadri

Advanced Aspects of Engineering Research Vol. 7, 6 May 2021, Page 123-134

Experimental investigation of supersonic base flow has been carried out to see the effect of the cylinder when rotated counter-clockwise inside the dead zone at variable locations near its base to control base pressure for different levels of expansion for area ratio 9. The cylinder of 2 mm diameter rotating counter-clockwise, when seen from the top, is mounted as a controller. Three locations are chosen from the sidewall of the square duct namely at 2, 4, 6 mm respectively, and one from the square nozzle exit at 8 mm in the base region to mount the controller. Base pressure in the recirculation zone and wall pressure along the square duct length has been measured with and without control. The experiments were carried out at Mach 2 for NPR 2, 3, 6, 7.8, and 8.5. Cylinder when rotated counter-clockwise as an active controller was found to reduce the base drag as high as 62 percent at NPR 8.5 when located near the duct wall and 50 percent when located away from the duct wall for the same NPR. For perfectly expanded flows at NPR 7.8 the reduction in base drag was approximately from 44 to 53 percent near the duct wall depending on the location of the controller. The active controller was up to 19 percent effective for over-expanded flows near the duct wall and up to 12 percent effective when located away from the duct wall. For under expanded flows at NPR 8.5 the base drag reduction was between 49 and 64 percent depending on the location of the controller. Also, the control did not adversely affect the flow field. Further flow visualization inside the duct was captured using a shadowgraph.

This paper presents a numerical and experimental study of increasing the performance coefficient (COP) of split AC (SAC) by reducing compressor work and increasing cooling capacity. Two phase ejector as an expansion device with a new design of dual evaporator temperature used. numerical methods apply the mathematical model developed in the EES software that is applied. Thermodynamic analysis is carried out to achieve ASHRAE Standard requirements for a minimum SAC with COP application of 3.5. The SAC system is filled with R-290 as a thermal fluid medium. Based on the simulation results a numerical model of the ejector is then produced and installed in a modified SAC system of cooling capacity of at least 9000 BTU/hour. An experimental test was conducted to investigate the actual performance of the ejector and its effect on the performance of the SAC system. The results showed that the two phase ejector with the new design of the dual evaporator temperature system was successful. When compared to standard split air conditioners using capillary tube expansion devices the tested ejector system contributes around 35% of power savings. The COP of the system can reach 5.5 which accounts for 39% of the increase in performance. Use of the constant ejector area COS-SAC dual temperature evaporator system which is intended to be applied for split AC to replace accumulator in standard ejector system has been successful.

The construction process is marred by project delays that tend to ruin the economies of nations worldwide. Studies pertaining to causes and effects of construction delays are plentiful, but solutions that was supposed to provide the results of this phenomenon (such as lean construction), is not seen to that scale. One reason for this is that delays are caused by time wastes at activity levels, and scholarly studies primarily don't deal at activity levels. Experience based heuristics play the most important role in fixing the duration of activates by managers. But, construction activities are prone to highly improbable & complex process flows, making heuristics unreliable. The reason being probability of one construction site condition and stakeholders, being similar to the next project is meagerly low. Thus experience gained by the project management personnel involved may not be handy in predicting actual durations and costs in the forthcoming project. The only practical solution would be fixation of cost and time standards for singular construction activities basing on the overall history of projects and personnel involved. On the long run globalizing or at least nationalizing heuristic data of delays and wastes would help in predicting future process. It can be achieved by proving a mechanism of the centralizing construction process into a single data entity at national level- Data Collection System (DCIS). As part of the system, synchronization of personnel and construction site data takes place at every instance a new construction process is activated anywhere in the concerned boundary of DCIS. Collection of inventory data, material data, labor data, stakeholder data, delay data, time waste data etc. is to form the epicenter of this data center. Data from heuristics should then be converted to mathematical distributions that can be used for predictions in future construction sites. This would result in giving better and better results as the process of data entry begins.