Abstract: With the growth of modern civilization and
industrialization in worldwide, the demand for energy is increasing
day by day. Majority of the world-s energy needs are met through
fossil fuels and natural gas. As a result the amount of fossil fuels is
on diminishing from year to year. Since the fossil fuel is nonrenewable,
so fuel price is gouging as a consequence of spiraling
demand and diminishing supply. At present the power generation of
our country is mainly depends on imported fossil fuels. To reduce the
dependency on imported fuel, the use of renewable sources has
become more popular. In Bangladesh coconut is widely growing tree.
Especially in the southern part of the country a large area will be
found where coconut tree is considered as natural asset. So, our
endeavor was to use the coconut oil as a renewable and alternative
fuel. This article shows the prospect of coconut oil as a renewable
and alternative fuel of diesel fuel. Since diesel engine has a versatile
uses including small electricity generation, an experimental set up is
then made to study the performance of a small diesel engine using
different blends of bio diesel converted from coconut oil. It is found
that bio diesel has slightly different properties than diesel. With
biodiesel the engine is capable of running without difficulty.
Different blends of bio diesel (i.e. B80, B60, and B 50 etc.) have
been used to avoid complicated modification of the engine or the fuel
supply system. Finally, a comparison of engine performance for
different blends of biodiesel has been carried out to determine the
optimum blend for different operating conditions.
Abstract: Titanium oxide hollow microspheres were synthesized from organic precursor titanium tetraisopropoxide (TTIP) using continuous spray pyrolysis reactor. Effects of precursor concentration, applied voltage and annealing have been investigated. It was observed that the annealing of the as-synthesized TiO2 hollow microspheres at 2500C, which had an average external diameter of 200 nm, leads to an increase in the size and also more spherical shape. The precursor concentration was found to have a direct impact on the size of the microspheres, which is also evident in the absorption spectrum. The as-prepared TiO2 hollow microspheres exhibited good photocatalytic activity for the degradation of MO.
Abstract: If a possibility distribution and a probability distribution
are describing values x of one and the same system or process
x(t), can they relate to each other? Though in general the possibility
and probability distributions might be not connected at all, we
can assume that in some particular cases there is an association linked
them.
In the presented paper, we consider distributions of bloodstream
concentrations of physiologically active substances and propose that
the probability to observe a concentration x of a substance X can be
produced from the possibility of the event X = x .
The proposed assumptions and resulted theoretical distributions
are tested against the data obtained from various panel studies of the
bloodstream concentrations of the different physiologically active
substances in patients and healthy adults as well.
Abstract: When choosing marketing strategies for international markets, one of the factors that should be considered is the cultural differences that exist among consumers in different countries. If the branding strategy has to be contextual and in tune with the culture, then the brand positioning variables has to interact, adapt and respond to the cultural variables in which the brand is operating. This study provides an overview of the relevance of culture in the development of an effective branding strategy in the international business environment. Hence, the main objective of this study is to provide a managerial framework for developing strategies for cross cultural brand management. The framework is useful because it incorporates the variables that are important in the competitiveness of fast food enterprises irrespective of their size. It provides practical, proactive and result oriented analysis that will help fast food firms augment their strategies in the international fast food markets. The proposed framework will enable managers understand the intricacies involved in branding in the global fast food industry and decrease the use of 'trial and error' when entering into unfamiliar markets.
Abstract: An analysis is made of the flow of an incompressible viscoelastic fluid (of small memory) over a porous plate subject to suction or blowing. It is found that velocity at a point increases with increase in the elasticity in the fluid. It is also shown that wall shear stress depends only on suction and is also independent of the material of fluids. No steady solution for velocity distribution exists when there is blowing at the plate. Temperature distribution in the boundary layer is determined and it is found that temperature at a point decreases with increase in the elasticity in the fluid.
Abstract: This paper presents a developed method for
controlling multi-renewable energy generators. The control system
depends basically on three sensors (wind anemometer, solar sensor,
and voltage sensor). These sensors represent PLC-s analogue inputs.
Controlling the output voltage supply can be achieved by an
enhanced method of interlocking between the renewable energy
generators, depending on those sensors and output contactors.
Abstract: In this paper a procedure for the split-pipe design of looped water distribution network based on the use of simulated annealing is proposed. Simulated annealing is a heuristic-based search algorithm, motivated by an analogy of physical annealing in solids. It is capable for solving the combinatorial optimization problem. In contrast to the split-pipe design that is derived from a continuous diameter design that has been implemented in conventional optimization techniques, the split-pipe design proposed in this paper is derived from a discrete diameter design where a set of pipe diameters is chosen directly from a specified set of commercial pipes. The optimality and feasibility of the solutions are found to be guaranteed by using the proposed method. The performance of the proposed procedure is demonstrated through solving the three well-known problems of water distribution network taken from the literature. Simulated annealing provides very promising solutions and the lowest-cost solutions are found for all of these test problems. The results obtained from these applications show that simulated annealing is able to handle a combinatorial optimization problem of the least cost design of water distribution network. The technique can be considered as an alternative tool for similar areas of research. Further applications and improvements of the technique are expected as well.
Abstract: This paper addresses one important aspect of
combustion system analysis, the spray evaporation and
dispersion modeling. In this study we assume an empty
cylinder which is as a simulator for a ramjet engine and the
cylinder has been studied by cold flow. Four nozzles have the
duties of injection which are located in the entrance of
cylinder. The air flow comes into the cylinder from one side
and injection operation will be done. By changing injection
velocity and entrance air flow velocity, we have studied
droplet sizing and efficient mass fraction of fuel vapor near
and at the exit area. We named the mass of fuel vapor inside
the flammability limit as the efficient mass fraction. Further,
we decreased the initial temperature of fuel droplets and we
have repeated the investigating again. To fulfill the calculation
we used a modified version of KIVA-3V.
Abstract: State-dependent Riccati equation based controllers are
becoming increasingly popular because of having attractive
properties like optimality, stability and robustness. This paper focuses
on the design of a roll autopilot for a fin stabilized and canard
controlled 122mm artillery rocket using state-dependent Riccati
equation technique. Initial spin is imparted to rocket during launch
and it quickly decays due to straight tail fins. After the spin phase, the
roll orientation of rocket is brought to zero with the canard deflection
commands generated by the roll autopilot. Roll autopilot has been
developed by considering uncoupled roll, pitch and yaw channels.
The canard actuator is modeled as a second-order nonlinear system.
Elements of the state weighing matrix for Riccati equation have been
chosen to be state dependent to exploit the design flexibility offered
by the Riccati equation technique. Simulation results under varying
conditions of flight demonstrate the wide operating range of the
proposed autopilot.
Abstract: A Personal Distributed Environment (PDE) is an
example of an IP-based system architecture designed for future
mobile communications. In a single PDE, there exist several Subnetworks
hosting devices located across the infrastructure, which will
inter-work with one another through the coordination of a Device
Management Entity (DME). Some of these Sub-networks are fixed
and some are mobile. In order to support Mobile Sub-networks
mobility in the PDE, the PDE-NEMO protocol was proposed. This
paper discussed the signalling cost analysis of PDE-NEMO by use of
a detailed simulation model. The paper started with the introduction
of the protocol, followed by the experiments and results and then
followed by discussions.
Abstract: The principal objective of a water treatment plant is to
produce water that satisfies a set of drinking water quality standards
at a reasonable price to the consumers. The gravel-bed flocculator
provide a simple and inexpensive design for flocculation in small
water treatment plants (less than 5000 m3/day capacity). The packed
bed of gravel provides ideal conditions for the formation of compact
settleable flocs because of continuous recontact provided by the
sinuous flow of water through the interstices formed by the gravel.
The field data which were obtained from the operation of the
water supply treatment unit cover the physical, chemical and
biological water qualities of the raw and settled water as obtained by
the operation of the treatment unit. The experiments were carried out
with the aim of assessing the efficiency of the gravel filter in
removing the turbidity, pathogenic bacteria, from the raw water. The
water treatment plant, which was constructed for the treatment of
river water, was in principle a rapid sand filter.
The results show that the average value of the turbidity level of
the settled water was 4.83 NTU with a standard deviation of turbidity
2.893 NTU. This indicated that the removal efficiency of the
sedimentation tank (gravel filter) was about 67.8 %. for pH values
fluctuated between 7.75 and 8.15, indicating the alkaline nature of
the raw water of the river Shatt Al-Hilla, as expected. Raw water pH
is depressed slightly following alum coagulation. The pH of the
settled water ranged from 7.75 to a maximum of 8.05.
The bacteriological tests which were carried out on the water
samples were: total coliform test, E-coli test, and the plate count test.
In each test the procedure used was as outlined in the Standard
Methods for the Examination of Water and Wastewater (APHA,
AWWA, and WPCF, 1985). The gravel filter exhibit a low
performance in removing bacterial load. The percentage bacterial
removal, which is maximum for total plate count (19%) and
minimum for total coliform (16.82%).
Abstract: In this paper, a new BiCMOS CCII and CCCII,
capable of operate at ±0.5V and having wide dynamic range with
achieved bandwidth of 480MHz and 430MHz respectively have been
proposed. The structures have been found to be insensitive to the
threshold voltage variations. The proposed circuits are suitable for
implementation using 0.25μm BiCMOS technology. Pspice
simulations confirm the performance of the proposed structures.
Abstract: A 7-step method (with 25 sub-steps) to assess risk of
air pollutants is introduced. These steps are: pre-considerations,
sampling, statistical analysis, exposure matrix and likelihood, doseresponse
matrix and likelihood, total risk evaluation, and discussion
of findings. All mentioned words and expressions are wellunderstood;
however, almost all steps have been modified, improved,
and coupled in such a way that a comprehensive method has been
prepared. Accordingly, the SADRA (Statistical Analysis-Driven Risk
Assessment) emphasizes extensive and ongoing application of
analytical statistics in traditional risk assessment models. A Sulfur
Dioxide case study validates the claim and provides a good
illustration for this method.
Abstract: Social interest and demand on Home-Network has
been increasing greatly. Although various services are being
introduced to respond to such demands, they can cause serious
security problems when linked to the open network such as Internet.
This paper reviews the security requirements to protect the service
users with assumption that the Home-Network environment is
connected to Internet and then proposes the security model based on
the requirement. The proposed security model can satisfy most of the
requirements and further can be dynamically applied to the future
ubiquitous Home-Networks.
Abstract: Col is a classic combinatorial game played on graphs
and to solve a general instance is a PSPACE-complete problem.
However, winning strategies can be found for some specific graph
instances. In this paper, the solution of Col on complete k-ary trees
is presented.
Abstract: The effect of chemical treatment in CdCl2 and thermal
annealing in 400°C, on the defect structures of potentially useful
ZnS\CdS solar cell thin films deposited onto quartz substrate and
prepared by vacuum deposition method was studied using the
Thermoluminesence (TL) techniques. A series of electron and hole
traps are found in the various deposited samples studied. After
annealing, however, it was observed that the intensity and activation
energy of TL signal increases with loss of the low temperature
electron traps.
Abstract: Adsorption of Toluidine blue dye from aqueous solutions onto Neem Leaf Powder (NLP) has been investigated. The surface characterization of this natural material was examined by Particle size analysis, Scanning Electron Microscopy (SEM), Fourier Transform Infrared (FTIR) spectroscopy and X-Ray Diffraction (XRD). The effects of process parameters such as initial concentration, pH, temperature and contact duration on the adsorption capacities have been evaluated, in which pH has been found to be most effective parameter among all. The data were analyzed using the Langmuir and Freundlich for explaining the equilibrium characteristics of adsorption. And kinetic models like pseudo first- order, second-order model and Elovich equation were utilized to describe the kinetic data. The experimental data were well fitted with Langmuir adsorption isotherm model and pseudo second order kinetic model. The thermodynamic parameters, such as Free energy of adsorption (AG"), enthalpy change (AH') and entropy change (AS°) were also determined and evaluated.
Abstract: This paper presents the experimental results of
discharge current phenomena on various humidity, temperature,
pressure and pollutant conditions of epoxy resin specimen. The
leakage distance of specimen was 3 cm, that it was supplied by high
voltage. The polluted condition was given with NaCl artificial
pollutant. The conducted measurements were discharge current and
applied voltage. The specimen was put in a hermetically sealed
chamber, and the current waveforms were analyzed with FFT.
The result indicated that on discharge condition, the fifth
harmonics still had dominant, rather than third one. The third
harmonics tent to be appeared on low pressure heavily polluted
condition, and followed by high humidity heavily polluted condition.
On the heavily polluted specimen, the peaks discharge current points
would be high and more frequent. Nevertheless, the specimen still
had capacitive property. Besides that, usually discharge current
points were more frequent. The influence of low pressure was still
dominant to be easier to discharge. The non-linear property would be
appear explicitly on low pressure and heavily polluted condition.
Abstract: Chevron frames (Inverted-V-braced frames or Vbraced
frames) have seismic disadvantages, such as not good exhibit force redistribution capability and compression brace buckles
immediately. Researchers developed new design provisions on
increasing both the ductility and lateral resistance of these structures
in seismic areas. One of these new methods is adding zipper columns, as proposed by Khatib et al. (1988) [2]. Zipper columns are
vertical members connecting the intersection points of the braces
above the first floor. In this paper applicability of the suspended
zipper system to Seismic Rehabilitation of Steel Structures is investigated.
The models are 3-, 6-, 9-, and 12-story Inverted-V-braced frames.
In this case, it is assumed that the structures must be rehabilitated. For rehabilitation of structures, zipper column is used. The result of
researches showed that the suspended zipper system is effective in
case of 3-, 6-, and 9-story Inverted-V-braced frames and it would
increase lateral resistance of structure up to life safety level. But in
case of high-rise buildings (such as 12 story frame), it doesn-t show
good performance. For solving this problem, the braced bay can
consist of small “units" over the height of the entire structure, which each of them is a zipper-braced bay with a few stories. By using this
method the lateral resistance of 12 story Inverted-V-braced frames is increased up to safety life level.
Abstract: This article discusses the concept of student ownership of knowledge and seeks to determine how to move students from knowledge acquisition to knowledge application and ultimately to knowledge generation in a virtual setting. Instructional strategies for fostering student engagement in a virtual environment are critical to the learner-s strategic ownership of the knowledge. A number of relevant theories that focus on learning, affect, needs and adult concerns are presented to provide a basis for exploring the transfer of knowledge from teacher to learner. A model under development is presented that combines the dimensions of knowledge approach, the teacher-student relationship with regards to knowledge authority and teaching approach to demonstrate the recursive and scaffolded design for creation of virtual learning environments.