KUET Institutional Repository (Khulna University of Engineering & Technology)
Not a member yet
1045 research outputs found
Sort by
Lightning Surge Analysis And Protection System Design For Typical Mobile Phone Tower
No full textThis thesis report submitted to the department of Electrical and
Electronic Engineering in partial fulfillment of the degree of
Master of Science in Electrical and Electronic Engineering, April 2018Cataloged from PDF Version of Thesis.Includes bibliographical references (pages 59-62).Lightning is not only a serious weather hazard but also it has fascinated and excited humans
for as long as they have watched the skies. It has been estimated that the earth is struck
by 100 lightning bolts every second. Now a days lightning hazard is an important issue
of major interest for the engineers and architects while designing the electric equipment &
tall structures. Analyses of lightning surge characteristics deserve much more importance
for designing protection scheme for communication tower against lightning. If a return
stroke hit upon any metallic structure such as communication tower suited on multi-storied
building’s roof, the lightning transient over voltage will propagate through the columns,
beams and other metallic structures of the building. If proper protection is not provided
against lightning, the building, electric equipment and also human being living inside the
building will be affected. Obviously this matter has been deserving much more attention for
public safety. Modern power and communication system includes many electronic appliances
for controlling and information processing purpose. It is essential to operate communication
systems utilizing these electronic appliances. In this research the lightning surge response
e.g, nature of voltage, current, surge impedance, electric field distribution and effect of direct
stroke in another word the lightning surge characteristics on the multi-storied building and
communication tower have been analysed. Induced effect of direct stroke on electronic
equipment inside the building on different floors has also been analysed. Two different
methods are used to analyzed the surge characteristics. Firstly Numerical Electromagnetic
Code (NEC-2) is used as simulation tool for finding the surge response. Secondly ATP Draw
(Alternative Transient Program) has been used for finding the surge characteristics. In this
research IEEE model, Pinceti model and Fernandes-Diaz model of MOV type surge arrester
are simulated with ATP-EMTP modified their parameters to determine the optimum values
for designing proper protection scheme for the typical mobile phone towers.Md. Zoyheroul IslamMaster of Science in Electrical and Electronic Engineerin
Study on Bioconversion of Household Waste and Faecal Sludge through Various Composting Process
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, November 2018.Cataloged from PDF Version of Thesis.Includes bibliographical references (pages 53-59).This research work is concerned on the preparation, characterization, analysis and
comparison of three types of compost, namely, (a) organic solid waste compost, (b) cocompost
of faecal sludge and organic solid waste and (c) vermicompost of faecal sludge and
organic solid waste ensuring SRDI (Soil Resource and Development Institute) standard. To
this purpose, solid waste was collected from the waste management plant established in the
campus of Khulna University of Engineering & Technology (KUET), while the faecal sludge
was collected from the septic tank of the KUET campus. Dried faecal sludge and organic
solid waste were mixed at a ratio of 1:3 to prepare co-compost using passively aeration
method. For vermicompost, Eisenia fetida, earthworm species was used. A 56 days cycle of
composting period was considered for maturation.
During composting cycle moisture and temperature plays an important role. So, temperature
of different composts was monitored carefully in this period. The peak temperature of all
composts was obtained within 7-8 days. Highest temperature of the composts was recorded
as 51°C for organic solid waste compost, 47°C for co-compost, 38°C for faecal sludge
vermicompost and 40°C for solid waste vermicompost. After that temperature starts to
decrease and finally merged with the ambient temperature.
Initially all compost samples consists of 3.00 kgs of sample except faecal sludge and solid
waste co-compost. To maintain the 1:3 ratio of faecal sludge nad solid waste, 1 kg dry faecal
sludge was mixed with 3.00 kg solid waste sample. The mass reduction is greater for solid
waste than faecal sludge. In case of solid waste compost the mass reduction is about 70%
(70.26% for solid waste compost and 70.43 for solid waste vermicompost). Whereas the
mass reduction of faecal sludge vermicompost and faecal sludge-solid waste co-compost is
41.53% and 58.82% respectively. Loss of moisture cintent is above 80% for solid waste
compost, solid waste vermicompost and faecal sludge and faecal sludge solid waste
vermicompost. But in case of faecal sludge vermicompost moisture reduction is 61.12%.
Similar condition is observed for voletile solids. The fixed solid reduction percentage is
4.47%, 6.43%, 11.99% and 4.94% for solid waste compost, solid waste vermicompost,
faecal sludge vermicompost and faecal sludge solid waste co-compost.
Initially composts were slight acidic except the co-compost of faecal sludge and organic
solid waste (8.3). at final condition all prepared composts were a little alkaline (pH was
above 7). Moisture content, total organic carbon and TVS decreased during composting
process. A reverse scenario was observed in case of fixed solids and total kjeldhal nitrogen
content. C/N ratio is an important indication of compost quality and maturity. According to
SRDI, C/N ratio of a finely matured organic fertilizer should be within 20. In this experiment,
C/N ratio of different composts were found as 10.29 for solid waste compost, 10.08 for solid
waste vermicompost, 12.25 for faecal sludge vermicompost and 10.67 for co-compost of
faecal sludge and organic solid waste. So, the C/N ratio values were within the SRDI
recommended values. A remarkable progress was observed in case of pathogen destruction.
At maturation stage the number of faecal coliform decreased by 50 times with respect to the
initial condition. Phosphorus content of vermicompost (1.34% for solid awste vermicompost
and 1.22% for faecal sludge vermicompost) was higher than the organic solid waste compost
(0.86%) and co-compost (0.96%). Faecal sludge vermicompost was recorded to have higher
potassium content than solid waste compost (0.8%), solid waste vermicompost (0.75%) and
co-compost (0.76%). But according to SRDI standard the potassium content of organic
fertilizer should be within 1-3%. Therefore, only faecal sludge vermicompost satisfied the
SRDI standard value for total potassium content.Tonmoy DebnathMaster of Science in Civil Engineerin
Evaluation of qualitative and quantitative techniques in decision-making: A Case Study
No full textThis thesis is submitted to the Department of Mechanical Engineering, Khulna University of Engineering & Technology in partial fulfillment of the requirements for the degree of Masters of Science in Engineering in Mechanical Engineering, December 2018.Cataloged from PDF Version of Thesis.Includes bibliographical references (pages 48-51).This paper represents a brief overview on the evaluation of qualitative and quantitative techniques in decision-making. The purpose of this study was to examine the status and extent to which administrators and engineers of Bangladesh apply qualitative and quantitative techniques of management in planning, directing, reporting and controlling activities for enhancing their administrative and operational decision-making capability. The study was directed to the top and operative organizational levels in two categories of administrators (executive and operative) to determine the types of managerial techniques used, degrees of familiarity with these techniques, frequency of use, managerial benefits and constraints, and individual and organizational factors involved in using such techniques. The qualitative and quantitative techniques were selected from diverse sources of related literature. The study followed guidelines of exploratory and descriptive research. Data were analyzed using statistics (mean and aggregated score) to describe administrator’s decision-making capability in terms of extent of utilization of the selected techniques. Based upon this study’s findings, practical implications are discussed. Limitations and suggestions also are made for future research into this topic.Faria Haque PushpoMasters of Science in Engineering in Mechanical Engineerin
Eff'ect of Lanthanum Substitution on the Structural, Magnetic and Transport Properties of 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 Masters of Science in Physics, November 2018.Cataloged from PDF Version of Thesis.Includes bibliographical references (pages 66-73).This thesis work is acquainted with the study of lanthanum (La) doped Cu-Zn ferrite. The
composition of the sample is Cu0.15Zn0.85LaxFe2-xO4 where it was prepared for x = 0.00,
0.02, 0.04, 0.06 and 0.08 content of La by Solid State Reaction method. The samples
were pre-sintered at 800oC for 3hours and sintered at 1150oC for 3 hours. The substitution
of La for various ratio have remarkable effects on the structural, magnetic and electrical
properties of Cu-Zn ferrite. The phase identification has carries out by using X-ray
diffraction (XRD). The XRD analysis revealed that undoped in Cu-Zn ferrite shows
formulation of cubic single phase (fcc) spinel structure without any impurity peak but
other four La doped Cu-Zn ferrites are shows additional peaks manifested the formation
of secondary phase presumably LaFeO3. The values of lattice parameter have the trend of
increasing with the increase of x. The bulk density also has a trend of increasing with the
increase of La content where the X-ray density decreases. In morphological study, SEM
image exhibit uniform surface morphology with well defined spherical grain. The average
grain size was calculated using Image J Software and it was observed that, the average
grain size decreases with increasing La content. The magnetic properties were studied by
investigating M-H curves that was obtained by vibrating sample magnetometer (VSM).
The magnetic properties demonstrated a strong dependence of the variation of x. With the
increase of x, saturation magnetization (Ms) decreases while remanent magnetization (Mr)
and coercivity (Hc) increases. The hysteresis curve for samples of various ratio of La
showed the ferromagnetic behavior. The decrease of Ms with increasing of La
substitutions has been explained as the effect of dilution of Fe3+ magnetic moment by
nonmagnetic La3+. The complex permeability, loss tangent, dielectric properties were
investigated as a function of frequency upto 120MHz by using impedance analyzer. The
initial permeability slightly increases with the increase of La substation while imaginary
permeability decreases. Moreover the dielectric constant decreases rapidly with the
increase in frequency at lower frequencies and slowly at higher frequency and almost
constant exhibiting normal behavior of ferrites. Dielectric constant decreases with
increases of La content in Cu-Zn ferrites. The electrical DC resistivity has a trend of
increasing with the increase of La content. The variation of electrical and dielectric in La
doped Cu-Zn ferrites are explained on the basis of Fe2+/Fe3+ ionic concentration with
affect La ions as well as the electronic hopping frequency between Fe2+ and Fe3+ ion.Kamrun NaharMasters of Science in Physic
Studies on Low cost Bio-Adsorbent in Wastewater Treatment
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, May 2018.Cataloged from PDF Version of Thesis.Includes bibliographical references (pages 105-115).Environmental pollution is a great concern in now a day. In modern time, with civilization and industrialization environmental pollution increases. Effluents of textile and dyeing industries pollute the environment directly and indirectly as well. Adsorption is one of the versatile techniques of removing waste. In the present investigation LBS Lima Bean Seed (LBS) (locally known as Rukuri in northern zone of Bangladesh) powder has been used as adsorbent for the removal of three textile reactive dyes, namely Reactive Magenta HB (RMHB), Active Orange P2R (AOP2R) and Reactive Red ME6BL (RRME6BL). It is observed that removal efficiency of RMHB, AOP2R and RRME6BL is high at lower pH (acidic medium). Though AOP2R and RRME6BL adsorbed at pH 2.0 and pH 3.0 respectively but in case of RMHB, it adsorbed relatively at higher pH, 6.0. Effect of concentration, adsorbent dose and contact time on adsorption process was observed. Removal of dyes increases with amount of adsorbent and time. But at in case of lower initial dye concentration dye removal rate was faster. Equilibrium time for the adsorption process was about 120 min. From the isotherm study it is observed that the applicability of the linear form of Langmuir and Freundlich model to LBS was confirmed by the high correlation coefficient R2 > 0.97. This suggests that the Langmuir isotherm and Freundlich models both provide good model of the sorption system. The value of 1/n was lower than 1, (n is greater than 1) indicating that studied dyes were favorably adsorbed by LBS. During the kinetics study it is seen that the plot of pseudo-first order has a high correlation coefficient than the plot of pseudo-second order. It should be mentioned, in both cases the value of R2 is close to the unity. More over the values of amount of adsorbate at equilibrium, qe dramatically differ from the experimental values in case of pseudo-second order. So, the adsorption of tested dyes on LBS is more appropriately followed the pseudofirst order model when compared with that of the pseudo-second order model. Study of Intraparticle diffusion model suggested that Intraparticle diffusion is not only Solo Rate Limiting Step.Md. Ruhul AminMaster of Philosophy in Chemistr