Abstract: This paper presents the effects of mixing procedures
on mechanical properties of flyash-based geopolymer matrices
containing nanosilica (NS) at 0.5%, 1.0%, 2.0%, and 3.0% by weight.
Comparison is made with conventional mechanical dry-mixing of NS
with flyash and wet-mixing of NS in alkaline solutions. Physical and
mechanical properties are investigated using X-Ray Diffraction
(XRD) and Scanning Electron Microscope (SEM). Results show that
generally the addition of NS particles enhanced the microstructure
and improved flexural and compressive strengths of geopolymer
nanocomposites. However, samples, prepared using dry-mixing
approach, demonstrate better physical and mechanical properties
comparing to wet-mixing samples.
Abstract: Low density polyethylene (LDPE) nanocomposites
with 3, 5 and 7 wt. % cobalt ferrite (CoFe2O4) nanopowder fabricated
with extrusion mixing and followed up by hot press to reach compact
samples. The transmission/reflection measurements were carried out
with a network analyzer in the frequency range of 8-12 GHz. By
increasing the percent of CoFe2O4 nanopowder, reflection loss (S11)
increases, while transferring loss (S21) decreases. Reflectivity (R)
calculations made using S11 and S21. Increase in percent of CoFe2O4
nanopowder up to 7 wt. % in composite leaded to higher reflectivity
amount, and revealed that increasing the percent of CoFe2O4
nanopowder up to 7 wt. % leads to further microwave absorption in
8-12 GHz range.
Abstract: The acceptance of sustainable products by the final
consumer is still one of the challenges of the industry, which
constantly seeks alternative approaches to successfully be accepted in
the global market. A large set of methods and approaches have been
discussed and analysed throughout the literature. Considering the current need for sustainable development and the
current pace of consumption, the need for a combined solution
towards the development of new products became clear, forcing
researchers in product development to propose alternatives to the
previous standard product development models. This paper presents, through a systemic analysis of the literature
on product development, eco-design and consumer involvement, a set
of alternatives regarding consumer involvement towards the
development of sustainable products and how these approaches could
help improve the sustainable industry’s establishment in the general
market. Still being developed in the course of the author’s PhD, the initial
findings of the research show that the understanding of the benefits of
sustainable behaviour lead to a more conscious acquisition and
eventually to the implementation of sustainable change in the
consumer. Thus this paper is the initial approach towards the
development of new sustainable products using the fashion industry
as an example of practical implementation and acceptance by the
consumers. By comparing the existing literature and critically analysing it, this
paper concluded that the consumer involvement is strategic to
improve the general understanding of sustainability and its features.
The use of consumers and communities has been studied since the
early 90s in order to exemplify uses and to guarantee a fast
comprehension. The analysis done also includes the importance of
this approach for the increase of innovation and ground breaking
developments, thus requiring further research and practical
implementation in order to better understand the implications and
limitations of this methodology.
Abstract: The nutritional composition and hypoglycaemic effect
of crackers produced from blend of sprouted pigeon pea, unripe
plantain and brewers’ spent grain and fed to Alloxan induced diabetic
rat was investigated. Crackers were produced from different blends of
sprouted pigeon pea, unripe plantain and brewers’ spent grain. The
crackers were evaluated for proximate composition, amino acid
profile and antinutritional factors. Blood glucose levels of normal and
diabetic rats fed with the control sample and different formulations of
cracker were measured. The protein content of the samples were
significantly different (p
Abstract: Journal bearings used in IC engines are prone to premature
failures and are likely to fail earlier than the rated life due to
highly impulsive and unstable operating conditions and frequent
starts/stops. Vibration signature extraction and wear debris analysis
techniques are prevalent in industry for condition monitoring of
rotary machinery. However, both techniques involve a great deal of
technical expertise, time, and cost. Limited literature is available on
the application of these techniques for fault detection in reciprocating
machinery, due to the complex nature of impact forces that
confounds the extraction of fault signals for vibration-based analysis
and wear prediction. In present study, a simulation model was developed to investigate
the bearing wear behaviour, resulting because of different operating
conditions, to complement the vibration analysis. In current
simulation, the dynamics of the engine was established first, based on
which the hydrodynamic journal bearing forces were evaluated by
numerical solution of the Reynold’s equation. In addition, the
essential outputs of interest in this study, critical to determine wear
rates are the tangential velocity and oil film thickness between the
journals and bearing sleeve, which if not maintained appropriately,
have a detrimental effect on the bearing performance. Archard’s wear prediction model was used in the simulation to
calculate the wear rate of bearings with specific location information
as all determinative parameters were obtained with reference to crank
rotation. Oil film thickness obtained from the model was used as a
criterion to determine if the lubrication is sufficient to prevent contact
between the journal and bearing thus causing accelerated wear. A
limiting value of 1 μm was used as the minimum oil film thickness
needed to prevent contact. The increased wear rate with growing
severity of operating conditions is analogous and comparable to the
rise in amplitude of the squared envelope of the referenced vibration
signals. Thus on one hand, the developed model demonstrated its
capability to explain wear behaviour and on the other hand it also
helps to establish a co-relation between wear based and vibration
based analysis. Therefore, the model provides a cost effective and
quick approach to predict the impending wear in IC engine bearings
under various operating conditions.
Abstract: The paper presents a method in which the expert
knowledge is applied to fuzzy inference model. Even a less
experienced person could benefit from the use of such a system, e.g.
urban planners, officials. The analysis result is obtained in a very
short time, so a large number of the proposed locations can also be
verified in a short time. The proposed method is intended for testing
of locations of car parks in a city. The paper shows selected examples
of locations of the P&R facilities in cities planning to introduce the
P&R. The analyses of existing objects are also shown in the paper
and they are confronted with the opinions of the system users, with
particular emphasis on unpopular locations. The results of the
analyses are compared to expert analysis of the P&R facilities
location that was outsourced by the city and the opinions about
existing facilities users that were expressed on social networking
sites. The obtained results are consistent with actual users’ feedback.
The proposed method proves to be good, but does not require the
involvement of a large experts team and large financial contributions
for complicated research. The method also provides an opportunity to
show the alternative location of P&R facilities. Although the results
of the method are approximate, they are not worse than results of
analysis of employed experts. The advantage of this method is ease of
use, which simplifies the professional expert analysis. The ability of
analyzing a large number of alternative locations gives a broader
view on the problem. It is valuable that the arduous analysis of the
team of people can be replaced by the model's calculation. According
to the authors, the proposed method is also suitable for
implementation on a GIS platform.
Abstract: In India, most of the pavement is laid by bituminous
road and the consumption of binder is high for pavement construction
and also modified binders are used to satisfy any specific pavement
requirement. Since the binders are visco-elastic material which is
having the mechanical properties of binder transition from viscoelastic
solid to visco-elastic fluid. In this paper, two different
protocols were used to measure the viscosity property of binder using
a Brookfield Viscometer and there is a need to find the appropriate
mixing and compaction temperatures of various types of binders
which can result in complete aggregate coating and adequate field
density of HMA mixtures. The aim of this work is to find the
transition temperature from Non-Newtonian behavior to Newtonian
behavior of the binder by adopting a steady shear protocol and the
shear rate ramp protocol. The transition from non-Newtonian to
Newtonian can occur through an increase of temperature and shear of
the material. The test has been conducted for unmodified binder VG
30. The transition temperature was found in the unmodified binder
VG is 120oC. Therefore, the application of both modified binder and
unmodified binder in the pavement construction needs to be studied
properly by considering temperature and traffic loading factors of the
respective project site.
Abstract: The statistical study has become indispensable for various fields of knowledge. Not any different, in Geotechnics the study of probabilistic and statistical methods has gained power considering its use in characterizing the uncertainties inherent in soil properties. One of the situations where engineers are constantly faced is the definition of a probability distribution that represents significantly the sampled data. To be able to discard bad distributions, goodness-of-fit tests are necessary. In this paper, three non-parametric goodness-of-fit tests are applied to a data set computationally generated to test the goodness-of-fit of them to a series of known distributions. It is shown that the use of normal distribution does not always provide satisfactory results regarding physical and behavioral representation of the modeled parameters.
Abstract: The purpose of this study is analyzing the relationship
between trust and social capital of people with using Social Network
Analysis. In this study, two aspects of social capital will be focused:
Bonding, homophilous social capital (BoSC), and Bridging,
heterophilous social capital (BrSC). These two aspects diverge each
other regarding to the social theories. The other concept of the study
is Trust (Tr), namely interpersonal trust, willing to ascribe good
intentions to and have confidence in the words and actions of other
people. In this study, the sample group, 61 people, was selected from
a private firm from the defense industry. The relation between
BoSC/BrSC and Tr is shown by using Social Network Analysis
(SNA) and statistical analysis with Likert type-questionnaire. The
results of the analysis show the Cronbach’s alpha value is 0.756 and
social capital values (BoSC/BrSC) is not correlated with Tr values of
the people.
Abstract: Computer education is referred to as the knowledge
and ability to use computers and related technology efficiently, with a
range of skills covering levels from basic use to advance. Computer
continues to make an ever-increasing impact on all aspect of human
endeavours such as education. With numerous benefits of computer
education, what are the insights of students on computer education?
This study investigated the perception of senior secondary school
students on computer education in Federal Capital Territory (FCT),
Abuja, Nigeria. A sample of 7500 senior secondary schools students
was involved in the study, one hundred (100) private and fifty (50)
public schools within FCT. They were selected by using simple
random sampling technique. A questionnaire [PSSSCEQ] was
developed and validated through expert judgement and reliability coefficient
of 0.84 was obtained. It was used to gather relevant data on
computer education. Findings confirmed that the students in the FCT
had positive perception on computer education. Some factors were
identified that affect students’ perception on computer education. The
null hypotheses were tested using t-test and ANOVA statistical
analyses at 0.05 level of significance. Based on these findings, some
recommendations were made which include competent teachers
should be employed into all secondary schools. This will help
students to acquire relevant knowledge in computer education,
technological supports should be provided to all secondary schools;
this will help the users (students) to solve specific problems in
computer education and financial supports should be provided to
procure computer facilities that will enhance the teaching and the
learning of computer education.
Abstract: The social logic of 'Sequina' slum area in Alexandria details the integral measure of space syntax at the room-level of twenty-building samples. The essence of spatial structure integrates the central 'visitor' domain with the 'living' frontage of the 'children' zone against the segregated privacy of the opposite 'parent' depth. Meanwhile, the multifunctioning of shallow rooms optimizes the integral 'visitor' structure through graph and visibility dimensions in contrast to the 'inhabitant' structure of graph-tails out of sight. Common theme of the layout integrity increases in compensation to the decrease of room visibility. Despite the 'pheno-type' of collective integration, the individual layouts observe 'geno-type' structure of spatial diversity per room adjoins. In this regard, the layout integrity alternates the cross-correlation of the 'kitchen & living' rooms with the 'inhabitant & visitor' domains of 'motherhood' dynamic structure. Moreover, the added 'grandparent' restructures the integral measure to become the deepest space, but opens to the 'living' of 'household' integrity. Some isomorphic layouts change the integral structure just through the 'balcony' extension of access, visual or ignored 'ringiness' of space syntax. However, the most integrated or segregated layouts invert the 'geno-type' into a shallow 'inhabitant' centrality versus the remote 'visitor' structure. Overview of the multivariate social logic of spatial integrity could never clarify without the micro-data analysis.
Abstract: River Hindon is an important river catering the
demand of highly populated rural and industrial cluster of western
Uttar Pradesh, India. Water quality of river Hindon is deteriorating at
an alarming rate due to various industrial, municipal and agricultural
activities. The present study aimed at identifying the pollution
sources and quantifying the degree to which these sources are
responsible for the deteriorating water quality of the river. Various
water quality parameters, like pH, temperature, electrical
conductivity, total dissolved solids, total hardness, calcium, chloride,
nitrate, sulphate, biological oxygen demand, chemical oxygen
demand, and total alkalinity were assessed. Water quality data
obtained from eight study sites for one year has been subjected to the
two multivariate techniques, namely, principal component analysis
and cluster analysis. Principal component analysis was applied with
the aim to find out spatial variability and to identify the sources
responsible for the water quality of the river. Three Varifactors were
obtained after varimax rotation of initial principal components using
principal component analysis. Cluster analysis was carried out to
classify sampling stations of certain similarity, which grouped eight
different sites into two clusters. The study reveals that the
anthropogenic influence (municipal, industrial, waste water and
agricultural runoff) was the major source of river water pollution.
Thus, this study illustrates the utility of multivariate statistical
techniques for analysis and elucidation of multifaceted data sets,
recognition of pollution sources/factors and understanding
temporal/spatial variations in water quality for effective river water
quality management.
Abstract: Fluctuations of Schottky diode parameters in a
structure of the mixer are investigated. These fluctuations are
manifested in two ways. At the first, they lead to fluctuations in the
transfer factor that is lead to the amplitude fluctuations in the signal
of intermediate frequency. On the basis of the measurement data of
1/f noise of the diode at forward current, the estimation of a spectrum
of relative fluctuations in transfer factor of the mixer is executed.
Current dependence of the spectrum of relative fluctuations in
transfer factor of the mixer and dependence of the spectrum of
relative fluctuations in transfer factor of the mixer on the amplitude
of the heterodyne signal are investigated. At the second, fluctuations
in parameters of the diode lead to occurrence of 1/f noise in the
output signal of the mixer. This noise limits the sensitivity of the
mixer to the value of received signal.
Abstract: By using a fixed point theorem of a sum operator, the
existence and uniqueness of positive solution for a class of
boundary value problem of nonlinear fractional differential equation
is studied. An iterative scheme is constructed to approximate it.
Finally, an example is given to illustrate the main result.
Abstract: This study evaluated to facilitate separation of ABS
plastics from other waste plastics by froth flotation after surface
hydrophilization of ABS with heat treatment. The mild heat treatment
at 100oC for 60s could selectively increase the hydrophilicity of the
ABS plastics surface (i.e., ABS contact angle decreased from 79o to
65.8o) among other plastics mixture. The SEM and XPS results of
plastic samples sufficiently supported the increase in hydrophilic
functional groups and decrease contact angle on ABS surface, after
heat treatment. As a result of the froth flotation (at mixing speed 150
rpm and airflow rate 0.3 L/min) after heat treatment, about 85% of
ABS was selectively separated from other heavy plastics with 100%
of purity. The effect of optimum treatment condition and detailed
mechanism onto separation efficiency in the froth floatation was also
investigated. This research is successful in giving a simple, effective,
and inexpensive method for ABS separation from waste plastics.
Abstract: Brushless DC motors (BLDC) are widely used in
industrial areas. The BLDC motors are driven either by indirect ACAC
converters or by direct AC-AC converters. Direct AC-AC
converters i.e. matrix converters are used in this paper to drive the
three phase BLDC motor and it eliminates the bulky DC link energy
storage element. A matrix converter converts the AC power supply to
an AC voltage of variable amplitude and variable frequency. A
control technique is designed to generate the switching pulses for the
three phase matrix converter. For the control of speed of the BLDC
motor a separate PI controller and Fuzzy Logic Controller (FLC) are
designed and a hysteresis current controller is also designed for the
control of motor torque. The control schemes are designed and tested
separately. The simulation results of both the schemes are compared
and contrasted in this paper. The results show that the fuzzy logic
control scheme outperforms the PI control scheme in terms of
dynamic performance of the BLDC motor. Simulation results are
validated with the experimental results.
Abstract: Average temperatures worldwide are expected to
continue to rise. At the same time, major cities in developing
countries are becoming increasingly populated and polluted.
Governments are tasked with the problem of overheating and air
quality in residential buildings. This paper presents the development
of a model, which is able to estimate the occupant exposure
to extreme temperatures and high air pollution within domestic
buildings. Building physics simulations were performed using the
EnergyPlus building physics software. An accurate metamodel is
then formed by randomly sampling building input parameters and
training on the outputs of EnergyPlus simulations. Metamodels are
used to vastly reduce the amount of computation time required when
performing optimisation and sensitivity analyses. Neural Networks
(NNs) have been compared to a Radial Basis Function (RBF)
algorithm when forming a metamodel. These techniques were
implemented using the PyBrain and scikit-learn python libraries,
respectively. NNs are shown to perform around 15% better than RBFs
when estimating overheating and air pollution metrics modelled by
EnergyPlus.
Abstract: The purposes of this study were to: 1) investigate
operation conditions of SME automotive part industry in Bangkok
and vicinity and 2) to compare operation problem levels of SME
automotive part industry in Bangkok and vicinity according to the
sizes of the enterprises. Samples in this study included 196
entrepreneurs of SME automotive part industry in Bangkok and
vicinity derived from simple random sampling and calculation from
R. V. Krejcie and D. W. Morgan’s tables. Research statistics included
frequency, percentage, mean, standard deviation, and T-test. The
results revealed that in general the problem levels of SME automotive
part industry in Bangkok and vicinity were high. When considering
in details, it was found that the problem levels were high at every
aspect, i.e. personal, production, export, finance, and marketing
respectively. The comparison of the problem levels according to the
sizes of the enterprises revealed statistically significant differences at
.05. When considering on each aspect, it was found that the aspect
with the statistical difference at .05 included 5 aspects, i.e.
production, marketing, finance, personal, and export. The findings
also showed that small enterprises faced more severe problems than
those of medium enterprises.
Abstract: This study investigated the effects of thermal
treatment on Tualang honey sample in terms of honey colour and
heat-induced small metabolites. The heating process was carried out
in a temperature controlled water batch at 90oC for 4 hours. The
honey samples were put in cylinder tubes with the dimension of 1 cm
diameter and 10 cm length for homogenous heat transfer. The results
found that the thermal treatment produced not only
hydroxylmethylfurfural, but also other harmful substances such as
phthalic anhydride and radiolytic byproducts. The degradation of
honey protein was due to the detection of free amino acids such as
cysteine and phenylalanine in heat-treated honey samples. Sugar
dehydration was also occurred because fragmented di-galactose was
identified based on the presence of characteristic ions in the mass
fragmentation pattern. The honey colour was found getting darker as
the heating duration was increased up to 4 hours. Approximately, 60
mm PFund of increment was noticed for the honey colour with the
colour change rate of 14.8 mm PFund per hour. Based on the
principal component analysis, the score plot clearly shows that the
chemical profile of Tualang honey was significantly altered after 2
hours of heating at 90oC.
Abstract: Bezier curves have useful properties for path
generation problem, for instance, it can generate the reference
trajectory for vehicles to satisfy the path constraints. Both algorithms
join cubic Bezier curve segment smoothly to generate the path. Some
of the useful properties of Bezier are curvature. In mathematics,
curvature is the amount by which a geometric object deviates from
being flat, or straight in the case of a line. Another extrinsic example
of curvature is a circle, where the curvature is equal to the reciprocal
of its radius at any point on the circle. The smaller the radius, the
higher the curvature thus the vehicle needs to bend sharply. In this
study, we use Bezier curve to fit highway-like curve. We use
different approach to find the best approximation for the curve so that
it will resembles highway-like curve. We compute curvature value by
analytical differentiation of the Bezier Curve. We will then compute
the maximum speed for driving using the curvature information
obtained. Our research works on some assumptions; first, the Bezier
curve estimates the real shape of the curve which can be verified
visually. Even though, fitting process of Bezier curve does not
interpolate exactly on the curve of interest, we believe that the
estimation of speed are acceptable. We verified our result with the
manual calculation of the curvature from the map.