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A Voting Scheme Based on Revised-SVRM and Confirmation Numbers
No full textThis thesis is submitted to the Department of Computer Science and Engineering, Khulna University of Engineering & Technology in partial fulfillment of the requirements for the degree of Masters of Science in Engineering in Computer Science and Engineering, February 2019.Cataloged from PDF Version of Thesis.Includes bibliographical references (pages 40-42).This thesis improves the performance of the revised-simplified verifiable re-encryption mixnet (R-SVRM) based e-voting scheme by introducing confirmation numbers (s) that are used in the based e-voting scheme. Although based and R-SVRM based schemes had made e-voting schemes more practical by excluding zero knowledge proof (ZKP) that requires large volume of computations, still they are not efficient enough. Namely, the based scheme adopts RSA encryption functions that are not probabilistic or commutative, therefore to satisfy essential requirements of elections, extra random factors are necessary for individual votes, election authorities must sign on votes and they must keep encryption keys as their secrets. On the other hand, although the R-SVRM based scheme uses ElGamal encryption functions that are probabilistic and commutative, vote forms in it is complicated, i.e. vote forms consist of at least 3 items and they include information about candidates as exponents. The improved scheme simplifies vote forms by exploiting s, and extensively reduces the number of operations required for individual votes. Also, the scheme successfully satisfies all essential requirements of e-voting systems, i.e. it is endowed with features about privacy, robustness, accuracy, incoercibility and fairness as based and RSVRM based schemes are.Masters of Science in Engineering in Computer Science and Engineerin
Synthesis, Characterization and Structural Optimization Using Density Functional Theory of Hydrazone Schiff Base Derivatives
No full textThis thesis is submitted to the Department of Chemistry, Khulna University of Engineering & Technology in partial fulfillment of the requirements for the degree of Masters of Science in Chemistry, January 2019.Cataloged from PDF Version of Thesis.Includes bibliographical references (pages 46-52).This thesis paper is related in an effective method for the addition of 2,4-dinitrophenyl hydrazine and various substituted 2,6-dibenzylidene cyclohexanone based bis-chalcones in the presence of hydrochloric acid to produce various hydrazone Schiffbase derivatives. First product, N[2,6bis(4:chlorobenzylidene)cyclohexylidene]-N'-(2,4-dinitrophenyl)-hydrazine has been synthesized by the reaction of 2,4-dinitrophenyihydrazine with 2,6-bis-(4-chlorobenzylidene)-cyclohexanone at reflux conditionat 2 hours. The isolated product was red in color and the melting point of the pure product was 185 °C. Second synthesized product. N-[2,6-bis-(4-methoxy-benzylidene)-cyclohexylidene]-N'-(2,4-dinitrophenyi)-hydrazifle has been synthesized by the reaction of 2,4-dinitrophenyl hydrazine with 2,6-bis-(4-methoxybenzylidene)-cyclohexanone at the same condition. The pure product was coffee color and the melting point of the pure product was 225 °C. Final product, N-[2,6-bis-(4-dirnethylamino-benzylidene)-cyclohexylidene]-N'-(2,4-dinitrophenyl)-hydrazifle has been synthesized by the reaction of 2,4-dinitrophenyihydrazine with 2,6-bis-(4-dimethylbenzylidene)-cyclohexanone also at the same condition. The product of the color was black and the melting point of the pure product was 245 °C. The structures of the synthesized products were characterized by their physical, UV, FTIR, 'H NMR & '3C NMR spectra. Their optimized structures have been investigated by computational method, Gaussian 16 software Revision B.01. Their molecular geometry and vibrational frequencies were computed at density functional theory, DFT-133LYP/6-3 1 1+G (2d, p) level of theory.Md. Zakaria HossainMasters of Science in Chemistr
A study on standard n-ideal of a lattice
No full textThis thesis is submitted to the Department of Mathematics, Khulna University of Engineering & Technology in partial fulfillment of the requirements for the degree of Master of Science in Mathematics, April 2019.Cataloged from PDF Version of Thesis.Includes bibliographical references (pages 49-50).Lattice theory is an important part of mathematics . Ideal lattice and n-ideal of a lattice have
played many roles in development of lattice theory. Historically, lattice theory started with
Boolean distributive lattices: as a result, the theory of ideal lattice and n-ideal of a lattice is
the most extensive and most satisfying chapter in the history of lattice theory. Ideal lattice
have provided the motivation for many results, in general lattice theory. Many conditions on
lattices and on element and ideals of lattices are weakened forms of distributivity is imposed
on lattices arising in various areas of mathematics, especially algebra.
In lattice theory there are different classes of lattices known as variety of lattices. Class of
Boolean lattice is of course most powerful variety. Throughout this thesis we will be
concerned with another large variety known as the class of ideal lattice and n-ideal of a lattice
have been studied by several authors.
The realization of special role of ideal lattices moved to break with the traditional approach to
lattice theory, which proceeds from partially ordered sets to general lattices, semi modular
lattices, modular lattices and finally ideal lattices.
In this thesis we give several result on ideal and n-ideal which will certainly extend and
generalize many results in lattice theory. In order to review, we include definations, examples,
solved problems and proof of some theorems. The thesis contains four chapter.
Chapter 1 we have discussed the basic defination of relation, poset, lattice, complete
lattice, convex sub lattice, complemented and relatively complemented lattice. We also proved
that, Dual of a complete lattice is complete .
Chapter 2 have discussed basic concept of ideal and n-ideal of lattice. Here we study the
defination and examples of ideal and n-ideal. Some imprtant theorem like “If n is a neutral
element of a lattice, then I (L) n is modular if and only if L is modular”.
Chapter 3 we have discussed Standard element and n-ideals. We also discussed in this
chapter Congruence relation.
Chapter 4 deals with standard n-ideal and Principal n-ideal. This is the main part of this
thesis work. In this chapter we have discussed some defination and some important theorems
like “For a neutral element n and a standard n-ideal S and an n-ideal I, S I is also a
standard n-ideal” .Md Imran HossenMaster of Science in Mathematic
Analytical Technique for Solving Second Order Generalized Strongly Nonlinear Duffing Equation with Varying Coefficients in Presence of Small Damping
No full textThis thesis is submitted to the Department of Mathematics, Khulna University of Engineering & Technology in partial fulfillment of the requirements for the degree of Master of Science in Mathematics, August 2019.Cataloged from PDF Version of Thesis.Includes bibliographical references (pages 28-31).In this thesis, we have extended He’s homotopy perturbation method for obtaining the
approximate analytical solution of second order generalized strongly nonlinear Duffing
equation with varying coefficients in presence of significant small damping based on the
extended form of the Krylov-Bogoliubov-Mitropolskii (KBM) method. Accuracy and
validity of the solutions obtained by the present method are compared with the
corresponding numerical solutions obtained by the well-known fourth order Runge-
Kutta method in graphically. The method has been illustrated by examples. In this study,
the present technique gives acceptable results avoiding any numerical complexity. The
results presented through figures show that the approximations are of extreme accuracy
with significant damping. The proposed method is simple and suitable for solving the
above mentioned nonlinear damped systems.Dipa KunduMaster of Science in Mathematic
Recovery and Characterization of Fuel from Pyrolysis of Medical Wastes: An Alternative Source of Energy
No full textThis thesis is submitted to the Department of Energy Science and Engineering, Khulna University of Engineering & Technology in partial fulfillment of the requirements for the degree of Master of Science in Engineering, December 2019.Cataloged from PDF Version of Thesis.Includes bibliographical references (pages 80-88).Bangladesh is a developing country and one of the most densely populated countries in the world. Energy consumption per capita of this country is also low compared to other developing nations. At present, the energy demands are becoming acute day by day. Environmental concerns and energy insufficiency led the government of the developing countries to think about innovative and nonconventional energy sources. Renewable energy sources may be a possible solution for meeting ever increasing energy demand as well as a way out of increasing environmental pollution. Various waste materials created from different sectors such as agricultural, industrial or medical sectors may also contribute to these matters. Inorganic materials like tyre waste are already contributing as a potential source of energy by deriving liquid and solid fuels through pyrolysis.
Appropriate and safe management of medical waste is acknowledged globally. Syringe/saline bottle wastes are mainly polyethelene and polypropelene plastic which are non-biodegradable and can create environmental pollution. Various typical problems are created to our surroundings by the disposal of such medical wastes. Sustainable management of such waste is important from various considerations. Lack of proper supervision of medical waste can cause some severe problems. The dumping of medical waste (syringe/saline bottle) into the drain is one of the main environmental issues in the municipal/city areas of Bangladesh. Blockage of drain and generation of mosquitoes and other bacteria are favoured by the disposal of such wastes in unplanned manner. The unmanaged recycling of infectious syringes and saline bottles represent a big threat to public health. Such circumstances are very likely to occur when medical waste is dumped in open space. Street children are chiefly at risk to come in contact with such wastes. Besides health-risk originated from direct contact, medical waste can harmfully affect the ecosystem by polluting water-bodies during waste treatment. Also, when such wastes are discarded in open areas close to water-bodies, they may become contaminated. So, deliberately this matters to the authority and researchers to manage these nonbiodegradable waste materials. So, a way to manage waste as well as extraction of fuel may be a good solution to this problem.
Management of medical waste is the accurate constraint, storage, treatment and dumping of infectious waste produced at human and animal health-care facilities. Adequate treatment procedures of medical waste are processes or techniques specifically designed to change the biological nature and composition/structure of medical waste. If this is done effectively, the wastes will no longer be contagious or biologically hazardous. The safe discarding and treatment of medical wastes have been ignored in Bangladesh. Land filling is largely used to manage medical waste which is not an appropriate option as dumped plastic wastes can cause serious damage to environment.
It is a shocking situation that waste produced inside the health-care facilities are collected by untrained cleaners without any separation in almost every city of Bangladesh. Then the cleaners dumped them into a hole or city corporation dustbin. Waste collectors use open basket or plastic bowl. Medical wastes are discarded in some open places, whereas rest of the waste is taken at the city corporation burning area. Open burning of medical waste is causing serious air pollution. Therefore, pyrolysis process can be a promising way out of this crisis. It will indirectly help to manage such non-biodegradable wastes, also low grade liquid fuels can be obtained. When waste materials are pyrolyzed, they generate oil, char and gas, which are valuable. The oil and char has adequate calorific value and can be used to produce heat energy.
In the present research, waste syringe/saline bottle were collected from the local clinics and hospitals of Khulna city areas and were pyrolyzed in a batch type reactor. Experiments on pyrolysis of syringe/saline bottles were conducted by changing the temperature within the range of 150-250° C at an interval of 50° C. The batch type fixed-bed pyrolysis reactor was constructed and installed in the Heat Engine Laboratory of the Department of Mechanical Engineering, Khulna University of Engineering & Technology. The maximum yield of pyrolytic oil and pyrolytic char from syringe waste was 35.94% (by weight) at 250° C and 51.08% (by weight) at 150° C with the feed size of 2×2 cm with loading size of 1.5 kg. The maximum yield of pyrolytic oil and pyrolytic char from saline bottle waste was 36.14% (by weight) at 250°C and 51.15% (by weight) at 150°C with the feed size of 2×2 cm with loading size of 1.5 kg.
The properties of pyrolytic oil from waste syringe/saline bottle such as density, kinematic viscosity, pour point, boiling point and cloud point were measured and the respective values are in the range of 726 to 758kg/m3 , 3.19 to 4.75cSt, -12 to -16° C, 86 to 95° C, -2 to 5°C and the gross calorific value (GCV) is around 42-44 MJ/kg which is comparable to diesel (42 to 46 MJ/kg). The GCV of pyrolytic char is around 42-43 MJ/kg which is comparable to anthracite coal (23 to 24 MJ/kg). The Gas chromatography-mass spectrometry (GC-MS) and Fourier Transform Infra-Red (FTIR) tests suggest presence of higher amount of aromatic compounds in pyrolytic oils evolved from the pyrolysis of syringe/saline bottle waste. The Thermogravimetric Analysis (TGA) shows that the experimental curve is higher from 150 to 300°C. The oil and char obtained from pyrolysis of syringe/saline bottle waste can be used as alternative fuel or chemical feedstock after some treatment. The results show that these properties are similar to that of the low grade liquid fuels and high grade solid fuels and thus pyrolysis of such waste (syringe/saline bottle) will reduce environmental contamination to a degree as well as be a substitute source of energy.Adnan AbedeenMaster of Science in Engineerin
Optimization of Investment Casting Parameters to Improve the Mechanical Properties by Taguchi Method
No full textThis thesis is submitted to the Department of Industrial Engineering and Management, Khulna University of Engineering & Technology in partial fulfillment of the requirements for the degree of Master of Science in Engineering in Industrial Engineering and Management, December 2019.Cataloged from PDF Version of Thesis.Includes bibliographical references (pages 34-37).In this present study investment casting process parameter is optimized by using Taguchi approach to improve the mechanical properties of mild steel. A set of experiments were conducted as per Taguchi's L9 orthogonal array to determine the most influential control factors, which will provide better and consistent for optimization to the casting's process parameters regardless of the noise factors present. For test the performance characteristics, orthogonal range, signal to noise ratio and variance analysis were used. Data values are obtained under the constraint of different process parameters like preheat temperature, pouring temperature, preheat time to investigate their effects on the surface hardness, tensile strength of the final results. The variations in the trend of the mechanical properties were observed and it was deduced out that high mold preheat temperature, higher pouring temperature, maximum preheat time significantly reduce the mechanical properties of castings produced by Taguchi method.Nil Ratan MondalMaster of Science in Engineering in Industrial Engineering and Managemen