Abstract: Waste silicon carbide (waste SiC) filled high-density
polyethylene (HDPE) with and without surface modifiers were
studied. Two types of surface modifiers namely; high-density
polyethylene-grafted-maleic anhydride (HDPE-g-MA) and 3-aminopropyltriethoxysilane have been used in this study. The
composites were produced using a two roll mill, extruder and shaped
in a hydraulic compression molding machine. The mechanical
properties of polymer composites such as flexural strength and
modulus, impact strength, tensile strength, stiffness and hardness
were investigated over a range of compositions. It was found that,
flexural strength and modulus, tensile modulus and hardness
increased, whereas impact strength and tensile strength decreased
with the increasing in filler contents, compared to the neat HDPE. At
similar filler content, the effect of both surface modifiers increased
flexural modulus, impact strength, tensile strength and stiffness but
reduced the flexural strength. Morphological investigation using
SEM revealed that the improvement in mechanical properties was
due to enhancement of the interfacial adhesion between waste SiC
and HDPE.
Abstract: A knowledge-based expert system with the acronym
RASPE is developed as an application tool to help decision makers in
construction companies make informed decisions about managing
risks in pipeline construction projects. Choosing to use expert
systems from all available artificial intelligence techniques is due to
the fact that an expert system is more suited to representing a
domain’s knowledge and the reasoning behind domain-specific
decisions. The knowledge-based expert system can capture the
knowledge in the form of conditional rules which represent various
project scenarios and potential risk mitigation/response actions. The
built knowledge in RASPE is utilized through the underlying
inference engine that allows the firing of rules relevant to a project
scenario into consideration. Paper provides an overview of the
knowledge acquisition process and goes about describing the
knowledge structure which is divided up into four major modules.
The paper shows one module in full detail for illustration purposes
and concludes with insightful remarks.
Abstract: In this paper, the effect of grades 32.4 and 42.5
Portland-limestone cements generally used for concrete production in
Nigeria on concrete compressive strength is investigated.
Investigation revealed that the compressive strength of concrete
produced with Portland-limestone cement grade 42.5 is generally
higher than that produced with cement grade 32.5. The percentage
difference between the compressive strengths of the concrete cubes
produced with Portland-limestone cement grades 42.5 and 32.5 is
inversely proportional to the richness of the concrete with the highest
and the least percentage difference associated with the 1:2:4 and
1:1:2 mix ratios respectively. It is recommended that cement grade
42.5 be preferred for construction in Nigeria as this will lead to the
construction of stronger concrete structures, which will reduce the
incidence of failure of building and other concrete structures at no
additional cost since the cost of both cement grades are the same.
Abstract: Solar energy is a good option among renewable
energy resources due to its easy availability and abundance. The
simplest and most efficient way to utilize solar energy is to convert it
into thermal energy and this can be done with the help of solar
collectors. The thermal performance of such collectors is poor due to
less heat transfer from the collector surface to air. In this work,
experimental investigations of single pass solar air heater having
triangular duct and provided with roughness element on the underside
of the absorber plate. V-shaped ribs are used for investigation having
three different values of relative roughness pitch (p/e) ranges from 4-
16 for a fixed value of angle of attack (α), relative roughness height
(e/Dh) and a relative gap distance (d/x) values are 60°, 0.044 and 0.60
respectively. Result shows that considerable augmentation in heat
transfer has been obtained by providing roughness.
Abstract: This research focused on comparing the critical
thinking of the teacher students before and after using Miller’s Model
learning activities and investigating their opinions. The sampling
groups were (1) fourth year 33 student teachers majoring in Early
Childhood Education and enrolling in semester 1 of academic year
2013 (2) third year 28 student teachers majoring in English and
enrolling in semester 2 of academic year 2013 and (3) third year 22
student teachers majoring in Thai and enrolling in semester 2 of
academic year 2013. The research instruments were (1) lesson plans
where the learning activities were settled based on Miller’s Model (2)
critical thinking assessment criteria and (3) a questionnaire on
opinions towards Miller’s Model based learning activities. The
statistical treatment was mean, deviation, different scores and T-test.
The result unfolded that (1) the critical thinking of the students after
the assigned activities was better than before and (2) the students’
opinions towards the critical thinking improvement activities based
on Miller’s Model ranged from the level of high to highest.
Abstract: The use OF adhesive anchors for wooden constructions is an efficient technology to connect and design timber members in new timber structures and to rehabilitate the damaged structural members of historical buildings. Due to the lack of standard regulation in this specific area of structural design, designers’ choices are still supported by test analysis that enables knowledge, and the prediction, of the structural behaviour of glued in rod joints. The paper outlines an experimental research activity aimed at identifying the tensile resistance capacity of several new adhesive joint prototypes made of epoxy resin, steel bar and timber, Oak and Douglas Fir species. The development of new adhesive connectors has been carried out by using epoxy to glue stainless steel bars into pre-drilled holes, characterised by smooth and rough internal surfaces, in timber samples. The realization of a threaded contact surface using a specific drill bit has led to an improved bond between wood and epoxy. The applied changes have also reduced the cost of the joints’ production. The paper presents the results of this parametric analysis and a Finite Element analysis that enables identification and study of the internal stress distribution in the proposed adhesive anchors.
Abstract: This study was conducted in the area of Vlora Bay,
Albania. Data about Sea Turtles Caretta caretta and Chelonia mydas,
belonging to two periods of time (1984 – 1991; 2008 – 2014) are
given. All data gathered were analyzed using recent methodologies.
For all turtles captured (as by catch), the Curve Carapace Length
(CCL) and Curved Carapace Width (CCW) were measured. These
data were statistically analyzed, where the mean was 67.11 cm for
CCL and 57.57 cm for CCW of all individuals studied (n=13). All
untagged individuals of marine turtles were tagged using metallic
tags (Stockbrand’s titanium tag) with an Albanian address. Sex was
determined and resulted that 45.4% of individuals were females,
27.3% males and 27.3% juveniles. All turtles were studied for the
presence of the epibionts. The area of Vlora Bay is used from marine
turtles (Caretta caretta) as a migratory corridor to pass from
Mediterranean to the northern part of the Adriatic Sea.
Abstract: In this study was monitored the population of the
European Pond Turtle, Emys orbicularis (Linnaeus, 1758) in the area
of Narta Lagoon, Vlora Bay (Albania), from August to October 2014.
A total of 54 individuals of E. orbicularis were studied using
different methodologies. Curved Carapace Length (CCL), Plastron
Length (PL) and Curved Carapace Width (CCW) were measured for
each individual of E. orbicularis and were statistically analyzed. All
captured turtles were separated in seven different size – classes based
on their carapace length (CCL). Each individual of E. orbicularis was
marked by notching the carapace (marginal scutes). Form all
individuals captured resulted that 37 were females (68.5%), 14 males
(25.9%), 3 juveniles (5.5%), while 18 individuals of E. orbicularis
were recaptured for the first and some for the second time.
Abstract: Teachers can play a huge role in encouraging students
to use computers and can affect students’ attitudes towards
computers. So understanding teachers’ beliefs and their use of
computers is an important way to create effective motivational
systems for teachers to use computers in the classroom in an effective
way. A qualitative study (6 focus group) was carried out among
Saudi High school teachers, both male and female, to examine their
attitudes towards computers and to find out their computer skills and
usage. The study showed a gender differences in that females were
less likely to attend computer workshops, females also had less
computer skills, and they have more negative attitudes towards
computers than males. Also the study found that low computer skills
in the classroom made students unlikely to have the lessons presented
using computers. Furthermore, the study found some factors that
effected teachers’ attitudes towards computers. These factors were
computer experience and confidence as much having skills and good
experience in computer use, the role and importance of computers
had become in their life and in teaching as well.
Abstract: One image is worth more than thousand words.
Images if analyzed can reveal useful information. Low level image
processing deals with the extraction of specific feature from a single
image. Now the question arises: What technique should be used to
extract patterns of very large and detailed image database? The
answer of the question is: “Image Mining”. Image Mining deals with
the extraction of image data relationship, implicit knowledge, and
another pattern from the collection of images or image database. It is
nothing but the extension of Data Mining. In the following paper, not
only we are going to scrutinize the current techniques of image
mining but also present a new technique for mining images using
Genetic Algorithm.
Abstract: This paper presents an adaptive thermal comfort
model study in the tropical country of Malaysia. A number of
researchers have been interested in applying the adaptive thermal
comfort model to different climates throughout the world, but so far
no study has been performed in Malaysia. For the use as a thermal
comfort model, which better applies to hot and humid climates, the
adaptive thermal comfort model was developed as part of this
research by using the collected results from a large field study in six
lecture halls with 178 students. The relationship between the
operative temperature and behavioral adaptations was determined. In
the developed adaptive model, the acceptable indoor neutral
temperatures lay within the range of 23.9-26.0C, with outdoor
temperatures ranging between 27.0-34.6C. The most comfortable
temperature for students in lecture hall was 25.7C.
Abstract: The study of the electrical signals produced by neural
activities of human brain is called Electroencephalography. In this
paper, we propose an automatic and efficient EEG signal
classification approach. The proposed approach is used to classify the
EEG signal into two classes: epileptic seizure or not. In the proposed
approach, we start with extracting the features by applying Discrete
Wavelet Transform (DWT) in order to decompose the EEG signals
into sub-bands. These features, extracted from details and
approximation coefficients of DWT sub-bands, are used as input to
Principal Component Analysis (PCA). The classification is based on
reducing the feature dimension using PCA and deriving the supportvectors
using Support Vector Machine (SVM). The experimental are
performed on real and standard dataset. A very high level of
classification accuracy is obtained in the result of classification.
Abstract: In this letter, we explore exact solutions for the
Horava-Lifshitz gravity. We use of an extension of this theory with
first order dynamical lapse function. The equations of motion have
been derived in a fully consistent scenario. We assume that there
are some spherically symmetric families of exact solutions of this
extended theory of gravity. We obtain exact solutions and investigate
the singularity structures of these solutions. Specially, an exact
solution with the regular horizon is found.
Abstract: The well been of human beings on construction site is
very important, many man power had been lost through accidents
which kills or make workers physically unfit to carry out construction
activities, these in turn have multiple effects on the whole economy.
Thus it is necessary to put all safety items and regulations in place
before construction activities can commence. This study was carried
out in Ondo state of Nigeria to known and analyse the state of health
and safety of construction workers in the state. The study was done
using first hand observation method, 50 construction project sites
were visited in 10 major towns of Ondo state, questionnaires were
distributed and the results were analysed. The result show that
construction workers are being exposed to a lot of construction site
hazards due to lack of inadequate safety programmes and nonprovision
of appropriate safety materials for workers on site. From the
data gotten for each site visited and the statistical analysis, it can be
concluded that occurrence of accident on construction sites depends
significantly on the available safety facilities on the sites. The result of
the regression statistics show that the level of significant of the
dependence of occurrence of accident on the availability of safety
items on site is 0.0362 which is less than 0.05 maximum significant
level required. Therefore a vital way of sustaining our building
strategy is by given a detail attention to provision of adequate health
and safety items on construction sites which will reduce the
occurrence of accident, loss of man power and death of skilled
workers among others.
Abstract: Interaction between human, location and activity
defines space. In the framework of these relations, space is a
container for current specifications in relations of the 3 mentioned
elements. The change of land utility considered with average
performance range, urban regulations, society requirements etc. will
provide welfare and comfort for citizens. From an engineering view it
is fundamental that choosing a proper location for a specific civil
activity requires evaluation of locations from different perspectives.
The debate of desirable establishment of municipal service elements
in urban regions is one of the most important issues related to urban
planning. In this paper, the research type is applicable based on goal,
and is descriptive and analytical based on nature. Initially existing
terminals in Esfahan are surveyed and then new locations are
presented based on evaluated criteria. In order to evaluate terminals
based on the considered factors, an AHP model is used at first to
estimate weight of different factors and then existing and suggested
locations are evaluated using Arc GIS software and AHP model
results. The results show that existing bus terminals are located in
fairly proper locations. Further results of this study suggest new
locations to establish terminals based on urban criteria.
Abstract: Modern low earth orbit (LEO) satellites that require multi-mission flexibility are highly likely to be repositioned between different operational orbits. While executing this process the satellite may experience high levels of vibration and environmental hazards, exposing the deployed solar panel to dangerous stress levels, fatigue and space debris, hence it is desirable to retract the solar array before satellite repositioning to avoid damage or failure.
A novel concept of deployable/retractable hybrid solar array systemcomposed of both rigid and flexible solar panels arranged within a petal formation, aimed to provide a greater power to volume ratio while dramatically reducing mass and cost is proposed.
Abstract: Fiber Bragg optic sensor is embedded in composite
material to detect and monitor the damage that occurs in composite
structures. In this paper, we deal with the mode-Ι delamination to
determine the material strength to crack propagation, using the
coupling mode theory and T-matrix method to simulate the FBGs
spectrum for both uniform and non-uniform strain distribution. The
double cantilever beam test is modeled in FEM to determine the
longitudinal strain. Two models are implemented, the first is the
global half model, and the second is the sub-model to represent the
FBGs with higher refined mesh. This method can simulate damage in
composite structures and converting strain to a wavelength shifting in
the FBG spectrum.
Abstract: This study was carried out to evaluate the nutritional
composition of the African River Prawn (Macrobrachium
vollenhovenii) in relation to Chokor (traditional) and Altona
(improved traditional) drying techniques used in the preservation and
processing of prawns by carrying out proximate composition
analysis. The value obtained for the proximate analysis of Chokor
and Altona smoke dried prawns were; Moisture (14.90% and
15.15%), Dry matter (85.10% and 84.85%), Protein (55.80% and
58.87%), Crude fat (1.95% and 1.98%), Crude fibre (21.40% and
13.11%), Carbohydrate (0.54% and 0.54%) and Ash (19.76% and
15.86%) respectively. The proximate mineral composition of Chokor
and Altona smoke dried prawns were; Calcium (5.66% and 4.20%)
and Phosphorus (9. 22% and 6.34%) respectively. Result shows there
was no loss of nutritional value with respect to Chokor and Altona
drying techniques used in the processing of prawns.
Abstract: Ocimum americanum L (Lamiaceae) is an annual herb
that is native to tropical Africa. The in vitro and in vivo antioxidant
activity of its aqueous extract was carefully investigated by assessing
the DPPH radical scavenging activity, ABTS radical scavenging
activity and hydrogen peroxide radical scavenging activity. The
reducing power, total phenol, total flavonoids and flavonols content
of the extract were also evaluated. The data obtained revealed that the
extract is rich in polyphenolic compounds and scavenged the radicals
in a concentration dependent manner. This was done in comparison
with the standard antioxidants such as BHT and Vitamin C. Also, the
induction of oxidative damage with paracetamol (2000 mg/kg)
resulted in the elevation of lipid peroxides and significant (P < 0.05)
decrease in activities of superoxide dismutase, glutathione
peroxidase, glutathione reductase and catalase in the liver and kidney
of rats. However, the pretreatment of rats with aqueous extract of O.
americanum leaves (200 and 400 mg/kg) and silymarin (100 mg/kg)
caused a significant (P < 0.05) reduction in the values of lipid
peroxides and restored the levels of antioxidant parameters in these
organs. These findings suggest that the leaves of O. americanum have
potent antioxidant properties which may be responsible for its
acclaimed folkloric uses.
Abstract: The present study was undertaken to investigate the
effect of aging parameters (time and temperature) on the mechanical
properties of Be-and/or Zr- treated Al-Mg-Zn (7075) alloys. Ultimate
tensile strength, 0.5% offset yield strength and % elongation
measurements were carried out on specimens prepared from cast and
heat treated 7075 alloys containing Be and/or Zr. Different aging
treatment were carried out for the as solution treated (SHT)
specimens (after quenching in warm water). The specimens were
aged at different conditions; Natural and artificial aging was carried
out at room temperature, 120C, 150C, 180C and 220C for different
periods of time. Duplex aging was performed for SHT conditions
(pre-aged at different time and temperature followed by high
temperature aging). Ultimate tensile strength, yield strength and %
elongation data results as a function of different aging parameters are
analysed. A statistical design of experiments (DOE) approach using
fractional factorial design is applied to acquire an understanding of
the effects of these variables and their interactions on the mechanical
properties of Be- and/or Zr- treated 7075 alloys. Mathematical
models are developed to relate the alloy mechanical properties with
the different aging parameters.