KUET Institutional Repository (Khulna University of Engineering & Technology)
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Improvement of Analytic Solution to the Inverse Truly Nonlinear Oscillator by Extended Iterative Method
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, February 2017.Cataloged from PDF Version of Thesis.Includes bibliographical references (pages 40-44).A new approach of the Mickens extended iterative method has been presented to obtain
approximate analytic solutions for nonlinear oscillatory differential equation. To get
modified approximate solution of the inverse nonlinear oscillator
“x+x-1=0” we have
used the Fourier series and utilized indispensable truncated terms in each iterative step. In
this thesis the solution gives more accurate result than other existing methods and shows a
good agreement with its exact solution. The percentage of error between exact frequency
and our third approximate frequency is as low as 0.0029%. We have compared our results
with exact results and other existing results and the solution is convergent as well as
consistent.Md. AsifuzzamanMaster of Science in Mathematic
An Experimental Study on Linear Fractional Programming Problems
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 Philosophy in Mathematics, January 2017.Cataloged from PDF Version of Thesis.Includes bibliographical references (pages 53-55).Much effort has been concentrated on transportation problems (TP) with equality constraints. In real life, however, most problems have mixed constraints accommodating many applications that go beyond transportation related problems to include job scheduling, production inventory, production distribution, allocation problems, and investment analysis. A literature search revealed no systematic method for finding an optimal solution or addressing more-for-less situations in transportation problems with mixed constraint. Here we consider modified VAM method to solve TP with mixed constraints to find out more-for-less situations in transportation problems. Several numerical examples have been considered to justify the effectiveness of the method.
On the other hand Linear Fraction Programming (LFP) (i.e. ratio objective that have numerator and denominator) have attracted the interest of many researches due to its application in many important fields such as production planning, financial and corporate planning, health care and hospital planning. Also various optimization problems in engineering and economics involve maximization (or minimization) of the ratio of physical or economical function, for instances cost/time, cost/volume, cost/benefit, profit/cost or other quantities measuring the efficiency of the system. This study presents a new approach for solving a fractional linear programming problem in which the objective function is a linear fractional function, while the constraint functions are in the form of linear inequalities. The LFP problem is converted it into a regular linear programming (LP) problem by an efficient way. The proposed approach is able to reduce some significant limitations of the existing methods. To test the effectiveness and efficiency of the algorithm some hard instances are considered. The proposed approach is able to solve the problem efficiently whereas in some cases the existence approaches are failed to solve the problems.Kazi Tanzila FerdausMaster of Philosophy in Mathematic
Development of Novel pH Sensor Based on Nanoparticle Modified Electrochemical Sensing Platform
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 Master of Science in Chemistry, April 2017.Cataloged from PDF Version of Thesis.Includes bibliographical references (pages 88-100)In biological and environmental applications, pH is an important parameter that needs to
monitor in regular basis. Conventionally, the measurement processes take a considerable
amount of time involving several calibration steps and handling of fragile electrodes. In
this work, we propose a new, robust and reliable way of sensing pH. The sensor has been
fabricated based on tungsten oxide nanoparticle modified glassy carbon electrode
(WO3/GCE). WO3 is a promising material for pH sensor because of its availability,
stability, good morphological and structural control of the synthesized nanostructures.
In this work, hydrothermal synthesis method was used for the fabrication of
WO3 nanoparticles. For the fabrication of the pH sensor, the nanoparticles were mixed
with Nafion and chitosan before drop coating onto the GCE surface. Scanning electron
microscopy (SEM), x-ray diffraction (XRD), energy dispersive x-ray spectroscopy (EDX)
and Raman spectroscopy were used to characterize the nanoparticle. Cyclic voltammetry
(CV), zero current potentiommetry (OCP) and square wave voltammetry (SWV) were
used to monitor the potential shift based on different pH in the buffer solutions. This
electrochemical pH sensor showed a sensitivity of 60 mVpH-1 and a potential drift of 2.4 –
5.0 % after three hours of continuous use. The sensor showed linearity range of pH 3 -11
and could retain 95% of its initial activity after 1 week of use. The electrode was found to
respond both in the presence and absence of oxygen, further expanding the potential
applications to include de-oxygenated environments. The WO3 based sensor showed good
sensitivity and long term stability, which would be a potential platform to develop a low
cost pH sensor for a wider range of applications.Irani AkhterMaster of Science in Chemistr
Study of the Surface Modified Co0.5Zn0.5Fe2O4 Nanoensembels for Biomedcal Application
No full textThis thesis is submitted to the Department of Physics, Khulna University of Engineering & Technology in partial fulfillment of the requirement for the degree of Master of Philosophy, October, 2017.Cataloged from PDF Version of Thesis.Includes bibliographical references (pages 113-129).Single domain magnetic nanomaterials with appropriate size and properties are interest for verity of biomedical and electrical applications such as magnetic hyperthermia, drug delivery, magnetic resonance imaging contrast enhancement, high-frequency electronics and high-density magnetic storage device. The superparamagnetic nanoparticles have their unique property, which can be manipulated and heated by an external ac magnetic field in order to destroy the cancer cells. In order to address this induction heating of MNPs (hyperthermia effect), we have prepared and characterized Co0.5Zn0.5Fe2O4 nano ensembles throughout this research work.
This research work deals with the synthesis of Co0.5Zn0.5Fe2O4 magnetic nanoparticles have been prepared using chemical co-precipitation methods. In order to investigate the annealing effects on their various physical properties, the prepared sample have been annealed at 2000C, 4000C, 6000C, 8000C and 10000C and then compared with the as-prepared sample. The XRD pattern of the as-dried and annealed samples exhibit single phase spinel structure with clear diffraction pattern. Enhancement in crystallite size from 7nn to 25nm is observed with the increase in annealing temperature from 2000C to 10000C respectively. VSM study reviled that as-prepared and annealed samples showed superparamegnetic behavior, which was further confirmed by the Mossbauer Spectroscopy. The saturation magnetization values of Co0.5Zn0.5Fe2O4 increased with the increase in annealing temperature, which confirmed that samples possess size and morphology dependent magnetic properties. Mossbauer spectra observed central doublet nature up to annealed sample 6000C and there is no hyperfine magnetic field is confirmed superparamagnetic behavior. The hydrodynamic diameter and the polydispersity index (PDI) were analyzed by DLS system at 370C and found to be between 173 nm and 231nm where PI is overall less than 0.3. For the hyperthermia study the result of induction heating measurements showed that the temperature raised by the 6mg/ml and 4mg/ml were 460C and 430C respectively. It has been seen that the rise in temperature due to the induction heating depends on the particle size and concentration of the nanoparticle. Finally, when coated with chitosan, these nanoparticle show a great ability to response to external field also suitability for biomedical application especially on hyperthermia therapy.Suman Halder129 pagesMaster of Philosophy in physic
Extraction of Biodiesel from Castor Oil and Study of Its Properties
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 Energy Science and Engineering, February 2017.Cataloged from PDF Version of Thesis.Includes bibliographical references (pages 74-78).Energy demand is increasing worldwide with expected fossil fuel shortages, alternative
energy resources need to be explored. Moreover, the high fossil energy utilization with its
unfavorable impact on environment and climate changes entitle for bio-fuels. In
Bangladesh energy consumption is increasing at a rapid rate due to rapid industrialization,
transportation and mechanization. Increasing pressure of population and increasing use of
energy in agriculture, industrial, domestic and public sectors is an area of concern. At the
same time, the need to meet energy demand has created huge capital requirements needed
for setting up power plants, pipe-lines, ports, terminals, railway tracks to move fuel etc.
Biodiesel fuel can be defined as medium length (C16 to C18) chains of fatty acids, and is
comprised mainly of mono-alkyl fatty acid esters. It is made through a chemical process
called transesterification where by the glycerin is separated from the fat or vegetable oil.
The process leaves behind two products: methyl esters (biodiesel) and glycerin.
In the present work the production of biodiesel from castor oil by transesterification of the
raw oil with methanol in the presence of H2SO4 and NaOH as catalyst. Castor oil (Ricinus
Communis L.) enclosed high value of fatty acid which makes transesterification process be
converted into methyl esters (biodiesel) due to high solubility in methanol. Biodiesel
produced from castor oil has been one of the most significant studies for current
researcher. Also methyl esters are transformed from castor oil by etherification process.
Various fuel properties of biodiesel produced from castor oil like density, viscosity, flash
point, fire point, pour point, calorific value were characterized and compared with the
properties of standard petro-diesel. It could be concluded that these oil from castor oil can
be used as a viable alternative to the diesel fuel.Mohammad Siddiqur RahmanMaster of Science in Energy Science and Engineerin
