Abstract: This paper presents the design and analysis of Liquid
Crystal (LC) based tunable reflectarray antenna with different design
configurations within X-band frequency range. The effect of LC
volume used for unit cell element on frequency tunability and
reflection loss performance has been investigated. Moreover different
slot embedded patch element configurations have been proposed for
LC based tunable reflectarray antenna design with enhanced
performance. The detailed fabrication and measurement procedure
for different LC based unit cells has been presented. The waveguide
scattering parameter measured results demonstrated that by using the
circular slot embedded patch elements, the frequency tunability and
dynamic phase range can be increased from 180MHz to 200MHz and
120° to 124° respectively. Furthermore the circular slot embedded
patch element can be designed at 10GHz resonant frequency with a
patch volume of 2.71mm3 as compared to 3.47mm3 required for
rectangular patch without slot.
Abstract: The study examines the influence of marital status on
consumers of products and services using blogs as a source of
information. A pre-designed questionnaire was used to collect the
primary data from the respondents (experiences). Data were collected
from one hundred and eighty seven respondents residing in and
around the Emirates of Sharjah and Dubai of the United Arab
Emirates. The collected data was analyzed with the help of statistical
tools such as averages, percentages, factor analysis, Student’s t-test
and Structural Equation Modelling Technique.
Objectives of the study are to know the reasons how married and
unmarried or single consumers of products and services are
motivated to use blogs as a source of information, to know whether
the consumers of products and services irrespective of their marital
status share their views and experiences with other bloggers and to
know the respondents’ future intentions towards blogging.
The study revealed the following: Majority of the respondents
have the motivation to blog because they are willing to receive
comments on what they post about services, convenience of blogs to
search for information about services and products, by blogging
respondents share information on the symptoms of a disease/ disorder
that may be experienced by someone, helps to share information
about ready to cook mix products and are keen to spend more time
blogging in the future.
Abstract: The need to extract R&D keywords from issues and use
them to retrieve R&D information is increasing rapidly. However, it is
difficult to identify related issues or distinguish them. Although the
similarity between issues cannot be identified, with an R&D lexicon,
issues that always share the same R&D keywords can be determined.
In detail, the R&D keywords that are associated with a particular issue
imply the key technology elements that are needed to solve a particular
issue.
Furthermore, the relationship among issues that share the same
R&D keywords can be shown in a more systematic way by clustering
them according to keywords. Thus, sharing R&D results and reusing
R&D technology can be facilitated. Indirectly, redundant investment
in R&D can be reduced as the relevant R&D information can be shared
among corresponding issues and the reusability of related R&D can be
improved. Therefore, a methodology to cluster issues from the
perspective of common R&D keywords is proposed to satisfy these
demands.
Abstract: This paper presents a regression model with
autocorrelated errors in which the inputs are social moods obtained by
analyzing the adjectives in Twitter posts using a document topic
model, where document topics are extracted using LDA. The
regression model predicts Dow Jones Industrial Average (DJIA) more
precisely than autoregressive moving-average models.
Abstract: A simple multi-wavelength passively Q-switched
Erbium-doped fiber laser (EDFL) is demonstrated using low cost
multi-walled carbon nanotubes (MWCNTs) based saturable absorber
(SA), which is prepared using polyvinyl alcohol (PVA) as a host
polymer. The multi-wavelength operation is achieved based on
nonlinear polarization rotation (NPR) effect by incorporating 50 m
long photonic crystal fiber (PCF) in the ring cavity. The EDFL
produces a stable multi-wavelength comb spectrum for more than 14
lines with a fixed spacing of 0.48 nm. The laser also demonstrates a
stable pulse train with the repetition rate increases from 14.9 kHz to
25.4 kHz as the pump power increases from the threshold power of
69.0 mW to the maximum pump power of 133.8 mW. The minimum
pulse width of 4.4 μs was obtained at the maximum pump power of
133.8 mW while the highest energy of 0.74 nJ was obtained at pump
power of 69.0 mW.
Abstract: The biomass-based fuels have become great concern in order to replace the petroleum-based fuels. Biofuels are a wide range of fuels referred to liquid, gas and solid fuels produced from biomass. Recently, higher chain alcohols such as 3-methyl-1-butanol and isobutanol have become a better candidate compared to bioethanol in order to replace gasoline as transportation fuel. Therefore, in this study, 3-methyl-1-butanol was produced through a fermentation process by yeast. Several types of yeast involved in this research including Saccharomyces cerevisiae, Kluyveromyces lactis GG799 and Pichia pastoris (KM71H, GS115 and X33). The result obtained showed that K. lactis GG799 gave the highest concentration of 3-methyl-1-butanol at 274 mg/l followed by S. cerevisiae, P. pastoris GS115, P. pastoris KM71H and P. pastoris X33 at 265 mg/l, 190 mg/l, 182 mg/l and 174 mg/l respectively. Based on the result, it proved that yeast have a potential in producing 3-methyl-1-butanol naturally.
Abstract: In the present work, detailed analysis on flow characteristics of a pair of immiscible liquids through horizontal pipeline is simulated by using ANSYS FLUENT 6.2. Moderately viscous oil and water (viscosity ratio = 107, density ratio = 0.89 and interfacial tension = 0.024 N/m) have been taken as system fluids for the study. Volume of Fluid (VOF) method has been employed by assuming unsteady flow, immiscible liquid pair, constant liquid properties, and co-axial flow. Meshing has been done using GAMBIT. Quadrilateral mesh type has been chosen to account for the surface tension effect more accurately. From the grid independent study, we have selected 47037 number of mesh elements for the entire geometry. Simulation successfully predicts slug, stratified wavy, stratified mixed and annular flow, except dispersion of oil in water, and dispersion of water in oil. Simulation results are validated with horizontal literature data and good conformity is observed. Subsequently, we have simulated the hydrodynamics (viz., velocity profile, area average pressure across a cross section and volume fraction profile along the radius) of stratified wavy and annular flow at different phase velocities. The simulation results show that in the annular flow, total pressure of the mixture decreases with increase in oil velocity due to the fact that pipe cross section is completely wetted with water. Simulated oil volume fraction shows maximum at the centre in core annular flow, whereas, in stratified flow, maximum value appears at upper side of the pipeline. These results are in accord with the actual flow configuration. Our findings could be useful in designing pipeline for transportation of crude oil.
Abstract: Abundant and cheap agricultural waste of oil palm trunk (OPT) juice was used to produce bioethanol. Two strains of Saccharomyces cerevisiae and a strain of Pichia stipitis were used to produce bioethanol from the OPT juice. Fermentation was conducted at previously optimized condition at 30oC and without shaking. The kinetic parameters were estimated and calculated. Monod equation and Hinshelwood model is used to relate the specific growth to the concentration of the limiting substrate and also to simulate bioethanol production rate. Among the three strains, single S. cerevisiae Kyokai no. 7 produce the highest ethanol yield of 0.477 g/l.h within the shortest time (12 h). This yeast also produces more than 20 g/l ethanol concentration within 10 h of fermentation.
Abstract: There is an essential need for obtaining the mathematical representation of fish body undulations, which can be used for designing and building new innovative types of marine propulsion systems with less environmental impact. This research work presents a case study to derive the mathematical model for fish body movement. Observation and capturing image methods were used in this study in order to obtain a mathematical representation of Clariasbatrachus fish (catfish). An experiment was conducted by using an aquarium with dimension 0.609 m x 0.304 m x 0.304 m, and a 0.5 m ruler was attached at the base of the aquarium. Progressive Scan Monochrome Camera was positioned at 1.8 m above the base of the aquarium to provide swimming sequences. Seven points were marked on the fish body using white marker to indicate the fish movement and measuring the amplitude of undulation. Images from video recordings (20 frames/s) were analyzed frame by frame using local coordinate system, with time interval 0.05 s. The amplitudes of undulations were obtained for image analysis from each point that has been marked on fish body. A graph of amplitude of undulations versus time was plotted by using computer to derive a mathematical fit. The function for the graph is polynomial with nine orders.
Abstract: The powders of Ba(Ce1-xZrx)0.90Y0.1O3-δ (BCZY) with 0.2 ≤ x ≤ 0.6 have been prepared by a modified sol-gel method. Triethylenetetramine (TETA) was employed as chelating agent. Phase formation of calcined powders at 1100oC and sintered pellets at 1400oC of BCZY were examined by an X-ray diffractrometer (XRD). XRD results showed the calcined powder and sintered pellet formed a single perovskite phase over the entire range of x values. As the amount of zirconium substitution (x values) increase, the main peaks are shifted to the higher 2theta values which suggest a complete substitution of zirconium into cerium sites. All the obtained calcined powders and sintered pellets possess cubic structure (Pm-3m) at all x values.
Abstract: An extensive amount of work has been done in data
clustering research under the unsupervised learning technique in Data
Mining during the past two decades. Moreover, several approaches
and methods have been emerged focusing on clustering diverse data
types, features of cluster models and similarity rates of clusters.
However, none of the single clustering algorithm exemplifies its best
nature in extracting efficient clusters. Consequently, in order to
rectify this issue, a new challenging technique called Cluster
Ensemble method was bloomed. This new approach tends to be the
alternative method for the cluster analysis problem. The main
objective of the Cluster Ensemble is to aggregate the diverse
clustering solutions in such a way to attain accuracy and also to
improve the eminence the individual clustering algorithms. Due to
the massive and rapid development of new methods in the globe of
data mining, it is highly mandatory to scrutinize a vital analysis of
existing techniques and the future novelty. This paper shows the
comparative analysis of different cluster ensemble methods along
with their methodologies and salient features. Henceforth this
unambiguous analysis will be very useful for the society of clustering
experts and also helps in deciding the most appropriate one to resolve
the problem in hand.
Abstract: Fluid rheology may have essential impact on sound propagation in a liquid-filled pipe, especially, in a low frequency range. Rheological parameters of liquid are temperature-sensitive, which ultimately results in a temperature dependence of the wave speed and attenuation in the waveguide. The study is devoted to modeling of this effect at sound propagation in an elastic pipe with polymeric liquid, described by generalized Maxwell model with non-zero high-frequency viscosity. It is assumed that relaxation spectrum is distributed according to the Spriggs law; temperature impact on the liquid rheology is described on the basis of the temperature-superposition principle and activation theory. The dispersion equation for the waveguide, considered as a thin-walled tube with polymeric solution, is obtained within a quasi-one-dimensional formulation. Results of the study illustrate the influence of temperature on sound propagation in the system.
Abstract: This paper presents the electrical effect of two neighboring distribution substation during the construction phase. The size of auxiliary grounding grid have an effect on entire grounding system. The bigger the size of auxiliary grounding grid, the lower the GPR and maximum touch voltage, with the exception that when the two grids are unconnected, i.e. the bigger the size of auxiliary grounding grid, the higher the maximum step voltage. The results in this paper could be served as design guideline of grounding system, and perhaps remedy of some troublesome grounding grids in power distribution’s system. Modeling and simulation is carried out on the Current Distribution Electromagnetic interference Grounding and Soil structure (CDEGS) program. The simulation results exhibit the design and analysis of power system grounding and perhaps could be set as a standard in grounding system design and modification in distribution substations.
Abstract: The purpose of this work is to optimize a Switched Reluctance Motor (SRM) for an automotive application, specifically for a fully electric car. A new optimization approach is proposed. This unique approach transforms automotive customer requirements into an optimization problem, based on sound knowledge of a SRM theory. The approach combines an analytical and a finite element analysis of the motor to quantify static nonlinear and dynamic performance parameters, as phase currents and motor torque maps, an output power and power losses in order to find the optimal motor as close to the reality as possible, within reasonable time. The new approach yields the optimal motor which is competitive with other types of already proposed motors for automotive applications. This distinctive approach can also be used to optimize other types of electrical motors, when parts specifically related to the SRM are adjusted accordingly.
Abstract: A theoretical study has been presented to describe the boundary layer flow and heat transfer on an exponentially shrinking sheet with a variable wall temperature and suction, in the presence of magnetic field. The governing nonlinear partial differential equations are converted into ordinary differential equations by similarity transformation, which are then solved numerically using the shooting method. Results for the skin friction coefficient, local Nusselt number, velocity profiles as well as temperature profiles are presented through graphs and tables for several sets of values of the parameters. The effects of the governing parameters on the flow and heat transfer characteristics are thoroughly examined.
Abstract: This paper presents development of the light-weight manipulator with series elastic actuation for medical telediagnostics (USG examination). General structure of realized impedance control algorithm was shown. It was described how to perform force measurements based mainly on elasticity of manipulator links.
Abstract: In this paper the vibration of a synchronous belt drive
during start-up is analyzed and discussed. Besides considering the
belt elasticity, the model here proposed also takes into consideration
the electromagnetic response of the DC motor. The solution of the
motion equations is obtained by means of the modal analysis in
state space, which allows to obtain the decoupling of all equations,
without introducing the hypothesis of proportional damping. The
mathematical model of the transmission and the solution algorithms
have been implemented within a computing software that allows the
user to simulate the dynamics of the system and to evaluate the effects
due to the elasticity of the belt branches and to the electromagnetic
behavior of the DC motor. In order to show the details of the
calculation procedure, the paper presents a case study developed with
the aid of the above-mentioned software.
Abstract: In this paper influence of packaging method (vacuum
and modified atmosphere packaging) on lipid oxidative stability and
sensory properties of odor and taste of the traditional sausage
Petrovská klobása were examined. These parameters were examined
during storage period (7 months). In the end of storage period,
vacuum packed sausage showed better oxidative stability. Propanal
content was significantly lower (P
Abstract: The concept of corporate social responsibility (CSR) in the Czech Republic has evolved notably during the last few years and an issue that started as an interest- and motive-based activity for businesses is becoming more commonplace. Governments have a role to play in ensuring that corporations behave according to the rules and norms of society and can legislate, foster, collaborate with businesses and endorse good practice in order to facilitate the development of CSR. The purpose of this paper is to examine the opportunities and options of CSR in government policy and research its relevance to a business sector. An increasing number of companies is engaging in responsible activities, the public awareness of CSR is rising, and customers are giving higher importance to CSR of companies in their choice. By drawing on existing CSR approach in Czech and understanding of CSR are demonstrated. The paper provides an overview, more detailed government approach of CSR.
Abstract: The Analytic Hierarchy Process is frequently used
approach for solving decision making problems. There exists wide
range of software programs utilizing that approach. Their main
disadvantage is that they are relatively expensive and missing
intermediate calculations. This work introduces a Microsoft Excel
add-in called DAME – Decision Analysis Module for Excel.
Comparing to other computer programs DAME is free, can work
with scenarios or multiple decision makers and displays intermediate
calculations. Users can structure their decision models into three
levels – scenarios/users, criteria and variants. Items on all levels can
be evaluated either by weights or pair-wise comparisons. There are
provided three different methods for the evaluation of the weights of
criteria, the variants as well as the scenarios – Saaty’s Method,
Geometric Mean Method and Fuller’s Triangle Method.
Multiplicative and additive syntheses are supported. The proposed
software package is demonstrated on couple of illustrating examples
of real life decision problems.