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: 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: 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: The belief of a heavenly God is enshrined to all
Abrahamic religions which form the three major religions of the
world today. Muslims believe in Allah who is above the seven
heavens. The youth in the United Arab Emirates (UAE) study Islamic
courses as part of their high school curriculum and are required to
take at least one Islamic course at the university level to gain credit
hours towards their general education (GENED). This paper provides
an insight of what the youth studying in the UAE think of where
Allah is. Our analysis shows that a big number of Muslim youth were
not sure, especially those from the Middle Eastern and Arab countries
bringing to conclusion that this subject needs to be revisited again in
the course work.
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: Background: The effectiveness of mirror therapy
(MT) has been investigated in acute hemiplegia. The present study
examines whether MT, given during chronic stroke, was more
effective in promoting motor recovery of the lower extremity and
walking speed than standard rehabilitation alone. Methods: The study
enrolled 30 patients with chronic stroke. Fifteen patients each were
assigned to the treatment group and the control group. All patients
received a conventional rehabilitation program for a 4-week period.
In addition to this rehabilitation program, patients in the treatment
group received mirror therapy for 4 weeks, 5 days a week. Main
measures: Passive ankle joint dorsiflexion range of motion, gait
speed, Brunnstrom stages of motor recovery, plantar flexor muscle
tone by Modified Ashworth Scale. Results: No significant difference
was found in the outcome measures among groups before treatment.
When compared with standard rehabilitation, mirror therapy
improved Ankle ROM, Brunnstrom stages and waking speed
(p < 0.05). However, there were no significant differences between
two groups on MAS (P > 0.05).Conclusion: Mirror therapy combined
with a conventional stroke rehabilitation program enhances lowerextremity
motor recovery and walking speed in chronic stroke
patients.
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: The 6th version of Universal modeling method for
centrifugal compressor stage calculation is described. Identification
of the new mathematical model was made. As a result of
identification the uniform set of empirical coefficients is received.
The efficiency definition error is 0,86 % at a design point. The
efficiency definition error at five flow rate points (except a point of
the maximum flow rate) is 1,22 %. Several variants of the stage with
3D impellers designed by 6th version program and quasi threedimensional
calculation programs were compared by their gas
dynamic performances CFD (NUMECA FINE TURBO).
Performance comparison demonstrated general principles of design
validity and leads to some design recommendations.
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: 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.
Abstract: This study concerned the dynamic behavior of the
wind turbine rotor. Before all we have studied the loads applied to the
rotor, which allows the knowledge their effect on the fatigue, also
studied the rotor with longitudinal crack in order to determine stress,
strain and displacement. Firstly we compared the first six modes
shapes between cracking and uncracking of HAWT rotor. Secondly
we show show evolution of first six natural frequencies with
longitudinal crack propagation. Finally we conclude that the residual
change in the natural frequencies can be used as in shaft crack
diagnosis predictive maintenance.
Abstract: Early detection of breast cancer saves many thousands
of lives each year via application of mammography and genetic
screening and many more lives could be saved if nurses are involved
in breast care screening practices. So, the aim of the study was to
identify nurse's role in early detection of breast cancer through
mammography and genetic screening and its impact on patient's
outcome. In order to achieve this aim, 400 women above 40 years,
asymptomatic were recruited for mammography and genetic
screening. In addition, 50 nurses and 6 technologists were involved in
the study. A descriptive analytical design was used. Five tools were
utilized: sociodemographic, mammographic examination and risk
factors, women's before, during and after mammography, items
relaying to technologists, and items related to nurses were also
obtained. The study finding revealed that 3% of women detected for
malignancy and 7.25% for fibroadenoma. Statistically significant
differences were found between mammography results and age,
family history, genetic screening, exposure to smoke, and using
contraceptive pills. Nurses have insufficient knowledge about
screening tests. Based on these findings the present study
recommended involvement of nurses in breast care which is very
important to in force population about screening practices.
Abstract: Speech enhancement is a long standing problem with
numerous applications like teleconferencing, VoIP, hearing aids and
speech recognition. The motivation behind this research work is to
obtain a clean speech signal of higher quality by applying the optimal
noise cancellation technique. Real-time adaptive filtering algorithms
seem to be the best candidate among all categories of the speech
enhancement methods. In this paper, we propose a speech
enhancement method based on Recursive Least Squares (RLS)
adaptive filter of speech signals. Experiments were performed on
noisy data which was prepared by adding AWGN, Babble and Pink
noise to clean speech samples at -5dB, 0dB, 5dB and 10dB SNR
levels. We then compare the noise cancellation performance of
proposed RLS algorithm with existing NLMS algorithm in terms of
Mean Squared Error (MSE), Signal to Noise ratio (SNR) and SNR
Loss. Based on the performance evaluation, the proposed RLS
algorithm was found to be a better optimal noise cancellation
technique for speech signals.