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A Novel Sensor for Simultaneous Detection of Dihydroxybenzene Isomers
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, August, 2016.Cataloged from PDF Version of Thesis.Includes bibliographical references (pages 130-142)A novel, facile and low-cost electrochemical technique for the detection of
dihydroxybenzene isomers (DHBIs), catechol (CC), hydroquinone (HQ) and resorcinol
(RS), in aqueous system was developed. An attempt was made for the analyses of HQ,
CC and RS in the same aqueous system by UV-Vis spectroscopy. UV-Vis spectrum of
CC, HQ and RS exhibited absorbance maxima in PBS supported aqueous solution at
275.4, 288.6 and 273.2 nm respectively. But in the possible binary and ternary mixture of
CC, HQ and RS, UV-Vis spectra showed single absorption peak instead of two and three
separate peaks respectively. So, simultaneous detection of DHBIs was impossible by
UV-Vis spectroscopy.
Three electrodes electrochemical system was employed which was controlled by
computer supported auto potentiostat. Cyclic voltammetry (CV) and differential pulse
voltammetry (DPV) were adopted as detection techniques. 2B pencil collected from the
local stationary shop was used for fabricating working electrode termed as pencil
graphite electrode (PGE) in the experiment. PGE electrode was characterized by
Scanning Electron Microscopy (SEM) and Energy-dispersive X-ray Spectroscopy
(EDX). From the SEM it was seen that surface morphology of PGE was not smooth as
conventional glassy carbon electrode (GCE) instead contained huge grooves as well. It
indicates that the graphite rod of the pencil was not pure crystalline. From EDX it was
seen that PGE surface are impure as propped up by SEM. Results showed that it is
composed of 79.39% carbon, 10.03% Si, 3.06% O2, 3.49% Al, 2.68% Fe and trace
amount of Mg and Ca. So a lot of defects and few foreign materials were present in the
surface of PGE confirmed by both SEM and EDX.
PGE was first modified electrochemically by ionic liquid (IL), [1-Hexylpyridinium
hexafluorophosphate (HIL) or 1-Butyl-3-Methylimidazolium hexafluorophosphate
(BIL)] and then used in detection analyte by CV and DPV. Modified electrodes were
termed as HIL-PGE and BIL-PGE in total working process. Modified electrodes showed
excellent electroanalytical activity effect on the redox reaction of DHBIs. Total analyses
and detection processes were performed in phosphate buffer solution (PBS) at pH 7.0
which was used as supporting electrolyte. The influences of scan rate and concentration
on the redox behavior of HQ, CC and RS in both HIL-PGE and BIL-PGE were
discussed. The anodic peak current versus the concentration of HQ, CC and RS showed a linear relationship. The variation of peak current was also plotted with Square root of
scan rate. The electrochemical processes were diffusion controlled. Variation of peak
potential separation was plotted with scan rate. The anodic peak potential shift was
positive, which was due to IR drop. HIL-PGE showed splendid selectivity and strong
anti-interference for detection of HQ, CC and RS simultaneously in aqueous media with
excellent results.
The limit of detection (LOD) was calculated by signal-to-noise ratio (S/N = 3). In
simultaneous detection, the LOD for HQ, CC and RS at HIL-PGE were 6.38 μML-1, 4.56
μML-1 and 19.6 μML-1 respectively and those were 9.09 μML-1, 8.15 μML-1 and 26.78
μML-1 respectively at BIL-PGE. The sensitivity for HQ, CC and RS is 448.49
μA/mM/cm2, 627.35 μA/mM/cm2 and 146.10 μA/mM/cm2 respectively at HIL-PGE and
525.21 μA/mM/cm2, 585.68 μA/mM/cm2 and 178.0 μA/mM/cm2 respectively at BILPGE
in simultaneous detection.Nusrat Tazeen TonuMaster of Science in Chemistr
Study on Distributive Lattice and Boolean Function
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, November 2016.Cataloged from PDF Version of Thesis.Includes bibliographical references (pages 67-68).In this thesis the nature of distributive lattice and Boolean function is studied.
Distributive lattices have played many roles in the development of lattice theory. Distributive
lattices have been studied by several authors including Abbott [6], Cornish [17], Nieminen
[10].A poset (L,£) is said to form a lattice if for every a,bÎL if sup{a,b} and inf{a,b} exist in
L . A lattice L is said to be distributive if "a,b,cÎ L ,
a Ù (b Ú c) = (a Ù b) Ú (a Ù c) holds.
In this thesis we give several results on distributive lattice and Boolean function which will
certainly extend and generalize many results in lattice theory. We have proved that N ´ N is
modular where N is the chain of naturals under usual £ . We also generalize the following
theorem of L.Nachbin[16], let L be a distributive lattice with 0 and 1 then L is Boolean iff all
its prime ideals are unordered by set inclusionÍ.Joyanta Kumar KunduMaster of Science in Mathematic
Development of Pavement Distress Models for Khulna – Jessore Highway in 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, July 2016.Cataloged from PDF Version of Thesis.Includes bibliographical references (pages 97-100)General function of a pavement is to provide a safe and comfortable riding surface to road
users. Pavements represent an important infrastructure to all countries. However, pavement
distress is major problems faced by road users. This pavement requires great care through
conducting periodic evaluation and timely maintenance to keep the pavement operating under
acceptable level of service. An adequate assessment of pavement distresses is necessary
before carrying out maintenance and rehabilitation.
Since maintenance of pavement is a vital and continuous activity, maintenance shall be done
effectively to avoid any reoccurrence and repeatedly works.Thus, in fulfill and meet pavement
goals,the aim of this study is to determine pavement distress model for effective maintenance
works in term of cost, quality and time at National Highway. These models allow pavement
authorities to predict the deterioration of the pavements and consequently determine the
maintenance needs and activities, predicting the timing of maintenance or rehabilitation, and
estimating the long range funding requirements for preserving the performance of the
network.In this study, data of pavement distresses on the Khulna - Jessore National Highway
(N7) were collected.Visual distress assessment using measuring tape, ruler and camera were
carried out on selected test sections of that highway in order to have better understanding of
the pavement response.These data were categorized, processed, and analyzed. These data
have been employed to generate pavement distress models by statistical software SPSS.
Throughout the study, the most common types of pavement distress on the national highway
have been identified. The behavior of these distress types has been investigated.A S-curve
regression equation was found to be an excellent representation of the data. Six for national
highway pavement distress models (NHPDM) have been developed.The developed models
provide a reasonable prediction of pavement condition. The models were assessed by
regression analysis.The implementation of the models for maintenance work has also been
proposed.S.M. Moazzem HossainMaster of Science in Civil Engineerin
Analysis of Dynamic Filtering Properties for Vocal-Tract during Bangla Vowel and Vowel-Consonant-Vowel Sequence Production
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, December, 2016.Cataloged from PDF Version of Thesis.Includes bibliographical references (pages 51-53).This thesis deals with the acoustic analysis of dynamic filtering properties for vocal-tract and the
perceptional space of Bangla vowel. Here we capture Bangla vowel, vowel-consonant-vowel
speech signal from native Bangla Speakers. Acoustic study of dynamic-shape of vocal-tract for
Bangla vowels and vowel-consonant-vowel (VCV) sequences are carried out based on dispersion
and cross-correlation of linear predictive coding (LPC) filtering coefficients and short-time
Fourier transform (STFT) of formant trajectory. The standard deviation of LPC filtering
coefficients and transitional energy of formant trajectories indicate the dynamics of vocal-tract.
The consonantal-constriction in VCV sequence accelerates the vocal-tract transitional nature and
the transitional nature yields lower-valued cross-correlation with more stable vowels. Fourier
transform technique is utilized to determine the cross-correlation of two unequal length LPC
trajectories. In the domain of vowel perception, speaker invariant principal components are
determined from the multidimensional perceptual space for comparatively stable Bangla vowels.
Linguistic content base multidimensional vector space can be formed using the formant
frequencies and its dispersion related statistical moments and the well reorganization-able
vowels may maintain a separable distance in the multidimensional space. In this work,
perceptual vectors and their associated energies are evaluated by determining the principal
components of the multidimensional space. Speaker invariance is numerically evaluated using
the correlation with principal components of native Bangla speakers. In this research, an
algorithm is also proposed for the determination of energy based on the redundancies of the
canonical variates for the inter-speaker vowel consistency.Sathi Rani MitraMaster of Science in Electrical and Electronic Engineerin
Performance Analysis of Narrow Band Spectrum Sensing Over Different Fading Channels in Cognitive Radio
No full textThis thesis paper is submitted to Department of Electronics and Communications Engineering, Khulna University of Engineering & Technology, Khulna, Bangladesh, in partial fulfillment of the requirements for the degree of “Master of Science”
in Electronics and Communication Engineering, August 2016.Cataloged from PDF Version of Thesis.Includes bibliographical references (pages 66-71).Due to rapid advancements in wireless communication the scarcity of radio spectrums are decreasing day by day. To ensure the future efficient wireless communication services, the radio spectrum management is a very important factor. To cope up with this demand, cognitive radio (CR) is a solution of huge prospect for spectrum sensing in order to detect and utilize empty spaces in the spectrum without creating interference to the primary users (PUs). The CR is referred to an intelligent and reconfigurable radio which enables efficient usages of unused spectrum while avoiding any kind of interference. Spectrum sensing is the key element in CR network for identifying the opportunity and to avoid the interference of PUs. The sensing methodology of spectrum depends upon its band of interest, surrounding environments, knowledge of pattern of PUs, required accuracy, required time of detection, power consumption and complexity & cost of the device.
This work focus on the formulation of mathematical system model for classical narrow band transmitter based detection which includes energy detector (ED) based sensing techniques, cyclostationary features detection and matched filtering and the simulation and performance analysis of their characteristics curve by MATLAB software. Finally, the work has recommended the best techniques for optimum performance of narrow band spectrum sensing over different fading environments.Md. Rasheduzzaman RashedMaster of Science in Electronics and Communication Engineerin
Detection of Neural Activity for Cerebrovascular Disease using MRI and EEG
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, August 2016.Cataloged from PDF Version of Thesis.Includes bibliographical references (pages 60-65).(CVD) such as stroke is the leading cause of long-term
disability and third most common reason of death in the world. Due to the neuronal
deficiency occurred by impaired blood flow to the brain, half of the stroke patients survive a
severe cognitive impairment such as impaired speech, numbness in limbs, immobilization of
limbs, visual impairment and many other observable symptoms. In the recent days, due to the
gradual increase of hypertensive and diabetic patient, the risk of developing stroke is growing
tremendously. The evaluation of actual neuronal status in stroke patient is thus very important
to determine the indication of neurosurgical treatment.
To diagnosis the type, source and location of stroke in the brain, generally, cerebral
blood flow (CBF) test, neuroimaging, and electrical activity test are being used. Among all of
these tests, electroencephalogram (EEG) is a useful tool for acute stroke detection and
monitoring affected tissue owing to its relatively cheap and completely hazardless for
quantitative and statistical analysis. Although a large number of studies have been performed
on the ischemic stroke using EEG, no investigation has been carried out on the interplay
between the infarcted cerebral hemisphere with other healthy part. Moreover, earlier studies
are also limited only age-related changes in EEG activity or memory performance compared
younger people between the ages of about 20 to 30 years with older participants between the
ages of about 60 to 80 years. There is also no study at all for the child below the age of 20
years to show the change and compare the neuronal deterioration of the infarcted part of
brain.
This work focused on the correlation between the extent of infarction and the clinical
effect to monitor the degree of hypo-activity of the affected part through the EEG analysis.
An indication for the assessment of neuronal activity and the degree of severity of stroke
patient has been proposed. A parallel study has also been carried out on healthy volunteers of
under fifteen years to find the comparison of neural activity between different age group.
From the analysis it is found that delta activities of EEG are highly unique of brain
pathophysiology, and preservation of alpha and beta frequencies following stroke is evidently
indicative of neuronal survival and a good prognosis. In order to assess brain
vi
pathophysiology in supratentorial brain lesion patients the delta/alpha ratio (DAR) and deltaplus-
theta to alpha-plus-beta ratio (DTABR) have also been used. It is observed that the DAR
and DTABR values of the left cerebral hemisphere of the patient are much higher than the
right cerebral hemisphere. It is also higher in both cerebral hemispheres than the control. A
threshold value of ~3.7 for DAR and ͂ 3.5 for DTABR has been obtained. It is observed that
DAR and DTABR of left hemisphere of patient are greater than 3.7and 3.5 respectively for
all the measurements indicating severe ischemic stroke in the fronto-temporal region of left
hemisphere. The findings have been further confirmed by a neuroimaging technique such as
magnetic resonance imaging (MRI).This study also show that DAR and DTABR of the
healthier child is~1.It is also found that delta and DAR indices of the old age are two times
more than the child indicating the diminishing of neuronal activity of old age is half of the
child. These results could be important for stroke diagnosis, prognosis, re-habitation
strategies, and proper neurosurgical treatment.G. M. Mahmudur RahmanMaster of Science in Biomedical Engineerin
Studies on the Physico-chemical Properties and Pharmacology of Heated Edible Oils
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, December 2016.Cataloged from PDF Version of Thesis.Includes bibliographical references (pages 87-97).The present study was carried out to evaluate the physico-cheniical properties like iodine value, acid value and compare FT-IR spectra of unheated and heated edible oils, the effects of consumption of heated edible oils diet oil blood lipid profile, biochemical parameters and hematological profile of rabbits. On the other hand, the present study aimed to observe the histological change in rabbit liver, kidney, heart, lung, brain and spleen tissues after feeding heated edible oils. The experimental data showed that the lowest iodine value and the highest acid value were observed in 20 hours heated palm oil (18.02±0.05), (7.01±0.03) and soybean oil (83.06±0.08),(5.68±0.05) respectively. The spectra of unheated and 2, 10, 20 hours heated palm and soybean oils showed very similar FT-JR spectra in this study. The body weight of experimental rabbit 20 hours heated palm oil diet group P3 (821.57±3.29 gm) and similar soybean oil diet group S3 (730.50±2.20 gm) were higher than that of control group. Total white blood cell (WBC) of 2 hours heated palm oil diet group P1 (9.5x10 3±0.16x103 blood cell/121), red blood cell (RBC) of P3 group (6.58±0.03 in! .tl), platelet count (PC) of 10 hours heated palm oil diet group P2 (593±2.44 thousand/jt!) were higher than that of fresh normal rabbits. Creatinine of S3 group (1.1±0.08 mg/dl), serum glutamic pyruvic transminase (SOPT) of P3 group (8 1±2.16 UIL), serum glutamic oxaloacetic transminase (SGOT) of P3 group (147±0.82 LJ/L) and uric acid of P2 group (1.9±0.08 mg/d!) were higher than that of control group. The total cholesterol (TC) of P3 group (158±2.16 mg!dl), high density lipoprotein (1-IDL) of P3 group (57±1.63 mg!dl), low density lipoprotein (LDL) of P3 group (8 1±1.41 mg/dl) and triglyceride (TG) of P3 group (176±0.82 mg/dl) were found higher than that of untreated rabbits. Histopathological study of liver, kidney, heart, lung, brain and spleen of the heated edible oil treated rabbits showed abnormalities as compared to control group organs. Consumption of heated edibles oil may occur infection, stress, allergy, hepatic damage, anemia, vascular disease, renal system damage, liver cirrhosis, pulmonary infarction, coronary artery disease of the consumers. Liver, heart, kidney, lung, brain, spleen and muscles may be damaged by chronic consumption of heated edible oils.Md. Raju AhmadMaster of Science in Chemistr
