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Analytical Solutions of Second Order Nonlinear Ordinary Differential Systems with high Order Nonlinearity
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, January 2016.Cataloged from PDF Version of Thesis.Includes bibliographical references (pages 25-30).Nonlinear oscillator models have been widely used in many areas of physics and engineering and are of significant importance in mechanical and structural dynamics for the comprehensive understanding and accurate prediction of motion.
The aim of the present study is to solve the second order autonomous Nonlinear Differential Systems with strong and high ((9th)) order nonlinearity in presence of small damping by combing He’s homotopy perturbation and the extended form of the KBM methods. The results obtained by the presented method are compared with those solutions obtained by the fourth order Runge-Kutta method in graphically.Deepa Rani GhoshMaster of Science in Mathematic
Preparation and characterization of chitosan based metal nanoparticles and study of their antibacterial property
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 Philosophy in Chemistry, August, 2016.Cataloged from PDF Version of Thesis.Includes bibliographical references (pages 64-78).Chitosan is a natural polysaccharide and has significant biological and chemical properties such as biodegradability, biocompatibility, bioactivity, microbial activity and polycationicity. In this research, chitosan based nanoparticles have been prepared for bacteriological application. Chitosan has been prepared and characterized from locally available waste shrimp shell. Prepared chitosan have been used as the raw material for the production of chitosan based metal nanoparticles such as Chitosan based zinc nanoparticle (Chi-Zn NPs), Chitosan based copper nanoparticle (Chi-Cu NPs) and Chitosan based cadmium nanoparticle (Chi-Cd NPs). First chitin has been has been isolated from shrimp shell by demineralization and deproteinization followed by deacetylation to get chitosan. Purity and characteristics of chitosan isolated from shrimp shell has been compared with those of extra pure chitosan purchased from Sisco Research Laboratories (SRL) Private Limited, India. It was characterized by Fourier Transform Infra Red (FTIR) Spectroscopy, solubility, moisture and ash content. It has been found that moisture and ash content of prepared chitosan is 1.25%, 1.22% respectively while those for purchased extra pure chitosan is 1.24% and 1.19%. Both are readily soluble in 1% acetic acid and produce transparent viscous solution. FTIR result of the extracted chitosan is very much comparable to the standard one. It has been seen that there is an excellent agreement between extracted and purchased chitosan. Chitosan based metal nanoparticles have been synthesizes by solution casting method. But the techniques and conditions are different from previous studies [83, 84]. The synthesized NPs were characterized by using FTIR, TGA and SEM analysis. FTIR spectra of the NPs (except Chi-Cd) are very similar to those of the synthesized chitosan. This indicates the presence of chitosan polymer in the NPs matrices. The loss of mass in TG analysis also confirms the presence of chitosan polymer in the Chi-Zn NPs. SEM photograph clearly showed the synthesized materials are nanomaterials within the range of 1-100 nm. Produced NPs exhibited enhanced antibacterial activities. Zone of inhibition against Pseudomonas aeruginosa, Salmonella bovismorbificans, Salmonella typhi and Escherichia coli bacteria of Chi-Zn, Chi-Cu, Chi-Cu(II) and Chi-Cd NPs are 38, 31, 30 and 39 mm; 32, 36, 37 and 32 mm; 30, 35, 36 and 33 mm and 35, 31, 31 and 38 mm respectively, while those for standard drug kanamycin are 22, 22, 20 and 20 mm respectively.Gazi Jahirul IslamMaster of Philosophy in Chemistr
Effect of Bi2O3 and V2O5 addition on Structural, Electrical transport and Electromagnetic properties of Ni-Cu-Zn Ferrites
No full textThis thesis is submitted to the Department of Physics, Khulna University of Engineering & Technology in partial fulfillment of the requirements for the degree of Master of Philosophy in Physics, December, 2016.Cataloged from PDF Version of Thesis.Includes bibliographical references (pages 107-117).Ni-Cu-Zn ferrites are well-known technological magnetic materials used for
manufacturing of multilayer chip inductor and applications in various electrical
devices. The present work is focused on the influence of substitutions and sintering
additive V2O5 and Bi2O3 on structural, transport and electromagnetic properties of NiCu-Zn ferrites. Two series of ferrite samples of the composition
Ni0.28Cu0.10Zn0.62Fe2O4 + x wt.% the concentration sintering additives were varies
0.2wt.% to 0.8wt.% for (i) V2O5 and (ii) Bi2O3 were prepared by using the solid state
reaction technique sintered at 1150oC and 1200oC with 6 hours holding time. The Xray diffraction analysis revealed that all the samples of the two series are crystalline in
single phase cubic spinel structure. Lattice parameter of Ni0.28Cu0.10Zn0.62Fe2O4 + x
wt.% V2O5 or Bi2O3 are slightly decrease with the increase of x content. The average
grain size of the samples increases with the increase of V2O5 additive content. On the
other hand grain growth by increasing Bi2O3 content inter diffusion as results after >
0.4wt.% Bi2O3 content abnormal grain growth. Curie temperature (Tc) and saturation
magnetization (Ms) are slightly increase with increasing V2O5 doped ferrite samples
up to x = 0.6 after decrease. On the other hand Tc decreases continuously with the
increase of Bi2O3 additive in the same ferrite samples. The magnetization process all
the samples are soft magnetic behavior. Initial permeability (µi) increases with the
increase of V2O5 at both sintering temperatures attaining maximum value for x = 0.4.
This enhancement of permeability may be correlated with improved microstructural
features. But the µi decreases with increasing doped Bi2O3 content in ferrite samples
and hence the highest value of quality factor is found for x = 0.4 within the range
20kHZ to 2MHz. The µi shows a flat profile from 1kHz to 4MHz indicating frequency
stability for all the ferrite samples. The improved electromagnetic properties of the
composition might be attributed to better densification and visible grain size. DC
resistivity decreases with increasing temperature. The dielectric constant is found to
decrease continuously with increasing frequency and remain almost constant at higher
frequency range. The dielectric behavior of the experiment ferrite samples explained
on the basis of the mechanism of the dielectric polarization and conduction process.Md. Abdul GofurMaster of Philosophy in Physic
Tumor and Its Stages Detection in Brain MRI Using Template Based K-means and Fuzzy C-means Clustering Algorithm
No full textThis thesis is submitted to the Department of Electronics and Communication Engineering, Khulna University of Engineering & Technology in partial fulfillment of the requirements for the degree of Master of Science in Electronics and Communication Engineering, January 2016.Cataloged from PDF Version of Thesis.Includes bibliographical references (pages 81-89).Segmentation is obligatory process in medical application for MRI image to detect brain tumour. This research work represents a robust segmentation method which is the integration of Template based K-means and modified Fuzzy C-means (TKFCM) clustering computed algorithm that, reduces the lack of operator performance, and error in equipment. In this method, the template is selected based on convolution between grey level intensity in small portion of brain image, and brain tumour image. K-means algorithm is to emphasized initial segmentation through the proper selection of template. Updated membership of FCM is obtained through distances from cluster centroid to cluster data points, until it reaches to its best. This Euclidian distance depends upon the different features i.e. intensity, entropy, contrast, dissimilarity and homogeneity of coarse image, which was depended only on similarity in conventional FCM. Then, on the basis of updated membership and automatic cluster selection, a sharp segmented image is obtained with red marked tumour from modified FCM technique. The small deviation of grey level intensity of normal and abnormal tissue is detected through TKFCM. For the tumor and its stages classification the linearization and region properties algorithm is needed to apply on detected tumor obtained from TKFCM, which provides the characteristics parameters like area, eccentricity, bounding box, perimeters and orientation. By these parameters the classified tumor and its stages are extracted. Besides the performances of TKFCM method is analyzed through neural network not only mathematically but also graphically. The resultant values give a better regression and least error compare to the other existing methods. This method will also help in detecting tumor in multiple intensity based brain MRI image.Rasel AhmmedMaster of Science in Electronics and Communication Engineerin
A Comparative Study on Fecal Sludge Management in Three Municipalities of Bangladesh
No full textThis thesis is submitted to the Department of Civil Engineering, Khulna University of Engineering & Technology in partial fulfillment of the requirements for the degree of Master of Science in Civil Engineering, October 2016.Cataloged from PDF Version of Thesis.Includes bibliographical references (pages 102-106).The sanitation needs of 2.7 billion people worldwide are served by onsite sanitation technologies, and that number is expected to grow to 5 billion by 2030. Bangladesh provides a striking example of progress to meet the Millennium Development Goal (MDG) - 7 to halve, by 2015, the “proportion of urban population with access to improved sanitation”. Open defecation has been reduced to only 1%, a milestone change from 42% in 2003. But the increase in fixed-place defecation has created an urgent need for Fecal Sludge Management (FSM) in the cities of Bangladesh, where most human waste is dumped untreated into waterways or onto marginal land, harming the health of the country’s poorest. The draft national regulatory framework identifies municipalities as responsible for FSM.
This research was carried out in Khulna City Corporation, Kushtia Municipality and Jhenaidah Municipality. The study involved data collection, field visits, fecal sludge sampling and laboratory analysis, investigation on emptying, treatment and disposal services.
Khulna City Corporation (KCC) covers an area of 45.65 km2 with tax-payee holdings of 66,257 of population 15,00,689. Manual sweepers are providing emptying services. KCC is providing both manual (by boggy) and mechanical emptying (vacutug) services since ten years. But there was no designated disposal site and the septage/fecal sludge was disposed here and there specially in drains which ultimately flows to river. 84% of the septic tanks have no soak wells and is connected directly to drains. Besides, City Corporation, Community Development Committee (CDC) have three smaller (1m3) vacutugs and those are much popular in services. Annual fecal sludge generation was estimated to be around 7,10,000 m3. Recently, KCC has started to construct a fecal sludge treatment plant (FTP) with financial assistance from Bill & Melinda Gates Foundation (BMGF).
Kushtia Municipality is a class “A” municipality and recently been extended to total land area of 42.79 sq.km with population 3,75,149. In this municipality, 68% septic tanks have no soak well and are connected to drains. Fecal sludge generation was estimated to be around 104,581 m3/year. In this municipality, vacutug services have been launched since ten years. They have a treatment plant with two drying beds and coco-peat filter and compost is being produced here. Recently, the emptying demand has been increased tremendously, but capacity of the treatment plant is less. Thus, another FTP is under planning to meet the additional demands for FSM.
Jhenaidah municipality is a small town of 32.42 Sq.km with 1,57,822 population. About 80% of the septic tanks have soak wells. Annual fecal sludge (FS) generation was estimated to be around 58,705 m3. A constructed wetland was built by the Department of Public Health Engineering (DPHE) in 2012 and handed over to the municipality for field operation and maintenance (O & M) using two vacutugs. But the municipality didn’t have any experience for the O & M of those and eventually left unused.
Characterization of FS has been done for three municipalities. Experiments have been performed for sixteen wastewater quality parameters for each FS sample such as solids concentration, chemical oxygen demand (COD), biochemical oxygen demand (BOD5), nutrients, pathogens, etc. The Solid contents in Fecal Sludge of these three towns varied between 3% to 6%. The range of COD concentrations were 7600-9600 mg/L. BOD5 concentrations were 819-1662 mg/L while the acceptable limit for disposal into inland water bodies is only 40 mg/L (ECR, 1997). Thus, it’s a big challenge to reduce the BOD5 in fecal sludge treatment plant for its ultimate disposal.
Based on the entire value chain of FSM in three municipalities, proposals have been suggested for the overall improvement. There are 38.3%, 46% and 54.5% of pit toilets in Khulna, Kushtia and Jhenaidah, respectively. Placement of water seal, Y-junction of pit toilets and proper maintenance of the toilets can keep the toilets hygienic and improved. In Khulna and Kushtia municipalities, around 84% and 68% of septic tanks, respectively are connected to drains and thus stringent regulatory enforcement seemed imperative for its control and revision following Bangladesh National Building Code (BNBC). Manual emptiers can be registered by Municipal Authority so that only they can provide the services ensuring health and safety. Small devices such as Gulper and Diaphragm-Pump for emptying, Excrevator/Augur for extracting the hard solids from bottom of septic tanks, promotion and encouragement of local manufacturing process of Vacutugs, provision of secondary transfer station (STS), FSM as market based solution, simple treatment technology, raising Social Awareness, addressing Health and Safety issues, etc. have been proposed for the improvement of fecal sludge management in the study areas.Md.Sahidul IslamMaster of Science in Civil Engineerin
Study of Radioactivity Levels in Different Kinds of Food Stuff Grown on the Bank of RupshaRriver and its Impact on Human Health
No full textThis thesis is submitted to the Department of Physics, Khulna University of Engineering & Technology in partial fulfillment of the requirements for the degree of Master of Science in Physics, April, 2016.Cataloged from PDF Version of Thesis.Includes bibliographical references (pages 109-113)The natural environment around us is the prime source of radiation. The activity
concentrations of radionuclide have been investigated in the human food-chain. To determine
the radioactivity level in the Paddy, Arum, Papaya &Leafy vegetables samples collected from
different locations on the Bank of Rupsha River at Rupsha upazialla in Khulna of Bangladesh.
In the present study, a total of 6 Paddy, 7 Leafy vegetables, 8 Arum and 7 Papaya samples
have been collected from 8 locations of the area under investigation. The samples have been
analyzed by gamma-ray spectrometry system using a ‘Hyper-Pure Germanium’ (HPGe)
detector of 20% relative efficiency to identify the probable radionuclides, activity
concentrations and the radiological risks to human from intake of these crops and vegetables.
Natural radionuclides such as 226Ra, 232Th and 40K have been found in the samples and no
artificial radionuclide has been detected in any of the sample.
The activity concentrations of 226Ra, 232Th and 40K in Paddy samples have been found to be
varied from 17.59±4.44 Bq/Kg to 42.32±4.48 Bq/Kg, average 24.43±5.16 Bq/Kg, BDL to
3.745±2.99, average 2.048±2.798 Bq/Kg and 35.97±150.34 Bq/Kg to 170.12±135.49 Bq/Kg,
average 93.96±133.75 Bq/Kg, respectively. In Leafy vegetables activity concentrations have
been found to be varied from 25.97±11.28 Bq/Kg to 49.11±13.48 Bq/Kg, average 34.22±12.55
Bq/Kg, BDL to 17.075±11.515 Bq/Kg, average 9.84±10.63 Bq/Kg and 626.88±176.34 Bq/Kg
to 1378.25±225.93 Bq/Kg, average 1110.50±200.24 Bq/Kg. In Arum samples activity
concentrations have been found to be varied from BDL to 8.78±3.08 Bq/Kg, average
5.77±2.97 Bq/Kg, BDL to 2.53±4.32 Bq/Kg and 426.91±107.23 Bq/Kg to
1280.71±133.89Bq/Kg, average 758.298±109.66 Bq/Kg. The activity concentrations in
Papaya samples have also been found to be varied from 13.295±9.64 Bq/Kg to 77.96±22.01
Bq/Kg, average 43.31±15.28 Bq/Kg, BDL to 26.2±17.27 Bq/Kg, average 15.44±11.28Bq/Kg
and 1112.65±202.33 Bq/Kg to 1712.47±221.96Bq/Kg, average 1490.27±226.27 Bq/Kg,
respectively. The annual effective dose of all samples (Paddy, Leafy vegetables, Arum and Papaya) have
been found that intake high effective Dose of 226Ra of 349.23 μSv y-1 by Papaya samples and
344.92 μSv y-1 by Leafy vegetables samples. 232Th of 248.29 μSv y-1 by Paddy samples & 40K
of 454.90 μSv y-1 by Arum samples. The maximum effective dose of 226Ra (0.39mSv) is high
than world safe value (0.12mSv) in Papaya, The effective dose of 40K (0.45mSv) is high than
world safe value (0.17mSv) in Arum and 232Th (0.24mSv) is slightly than world safe
value(0.12mSv) in Paddy samples. The natural radioactivity concentrations of 226Ra, 232Th and
40K for all samples are higher than the worldwide average values. The current result is slightly
higher compared with the results of similar studies undertaken in other countries and in
different places in Bangladesh. However, these values of doses are much below the
permissible level set by ICRP, and, therefore, there is no immediate health risk on workers
and public due to natural radioactivity present in the samples of the study area.
Therefore, the results on radionuclide concentrations and annual effective dose have been
obtained from this study may provide with interesting information to evaluate the extent,
degree and routes of the radiological impact. This study would also be useful as a base line
data on radiation exposure and environmental impact caused by crops and vegetables on the
Bank of Rupsha River in Khulna of Bangladesh.Mst. Nur NaharMaster of Science in Physic
Design and Analysis of Grid-Connected Hybrid Power Systems Based on Renewable Energy: Bangladesh Perspective
No full textThis thesis is submitted to the Department of Electrical and Electronic Engineering, Khulna University of Engineering & Technology in partial fulfillment of the requirements for the degree of Master of Science in Electrical and Electronic Engineering, July 2016.Cataloged from PDF Version of Thesis.Includes bibliographical references (pages 108-115).Current power generation scenarios all over the world are not climate friendly as the
generation systems are mainly dependent on fossil fuels that produce greenhouse gas (GHG)
which contributes to global warming. This thesis presents an economical expediency of gridconnected
hybrid (PV/Wind turbine) power system model by investigating the potentials of
the wind and solar energy. It also conducts a feasibility analysis to explore the potentialities
of green energy at different locations namely Kuakata, Sitakunda, Magnamaghat, Dinajpur,
Rangpur and Khulna in Bangladesh. Initially, a flowchart of the proposed hybrid power
system model is developed and then a hybrid model is designed with varying the
contributions of renewable resources for the considered coastal region and the northern part
of Bangladesh using a software tool named Hybrid Optimization of Multiple Energy
Resources (HOMER). The simulation results are calculated for finding the cost of energy
(COE), net present cost (NPC), total annualize cost, annual real interest rate, capital recovery
factor (CRF), fraction of renewable energy (RE) contribution and greenhouse gas emission in
terms of tons/year from which an optimum combination of RE sources and fraction of
different RE sources in the designed hybrid power plant are determined. Sensitivity variables,
such as range of wind speed, solar radiation, PV panel price, wind turbine hub height, are
defined as inputs during simulation. The optimization process is carried out repeatedly for the
sensitivity variables and the results are refined accordingly. Also, a comparison is made
between off-grid and grid connected models on the basis of COE and GHG emission. The
simulation results show that the proposed grid-PV-wind hybrid power system model is most
suitable, economical and eco-friendly for the considered regions in Bangladesh.Md. Nurunnabi
