Abstract: This paper presents the performance characteristics of
Darrieus-type vertical axis wind turbine (VAWT) with NACA airfoil
blades. The performance of Darrieus-type VAWT can be
characterized by torque and power. There are various parameters
affecting the performance such as chord length, helical angle, pitch
angle and rotor diameter. To estimate the optimum shape of Darrieustype
wind turbine in accordance with various design parameters, we
examined aerodynamic characteristics and separated flow occurring
in the vicinity of blade, interaction between flow and blade, and
torque and power characteristics derived from it. For flow analysis,
flow variations were investigated based on the unsteady RANS
(Reynolds-averaged Navier-Stokes) equation. Sliding mesh algorithm
was employed in order to consider rotational effect of blade. To
obtain more realistic results we conducted experiment and numerical
analysis at the same time for three-dimensional shape. In addition,
several parameters (chord length, rotor diameter, pitch angle, and
helical angle) were considered to find out optimum shape design and
characteristics of interaction with ambient flow. Since the NACA
airfoil used in this study showed significant changes in magnitude of
lift and drag depending on an angle of attack, the rotor with low drag,
long cord length and short diameter shows high power coefficient in
low tip speed ratio (TSR) range. On the contrary, in high TSR range,
drag becomes high. Hence, the short-chord and long-diameter rotor
produces high power coefficient. When a pitch angle at which airfoil
directs toward inside equals to -2° and helical angle equals to 0°,
Darrieus-type VAWT generates maximum power.
Abstract: The cities of Johannesburg and Pretoria both located in the Gauteng province are separated by a distance of 58 km. The traffic queues on the Ben Schoeman freeway which connects these two cities can stretch for almost 1.5 km. Vehicle traffic congestion impacts negatively on the business and the commuter’s quality of life. The goal of this paper is to identify variables that influence the flow of traffic and to design a vehicle traffic prediction model, which will predict the traffic flow pattern in advance. The model will unable motorist to be able to make appropriate travel decisions ahead of time. The data used was collected by Mikro’s Traffic Monitoring (MTM). Multi-Layer perceptron (MLP) was used individually to construct the model and the MLP was also combined with Bagging ensemble method to training the data. The cross—validation method was used for evaluating the models. The results obtained from the techniques were compared using predictive and prediction costs. The cost was computed using combination of the loss matrix and the confusion matrix. The predicted models designed shows that the status of the traffic flow on the freeway can be predicted using the following parameters travel time, average speed, traffic volume and day of month. The implications of this work is that commuters will be able to spend less time travelling on the route and spend time with their families. The logistics industry will save more than twice what they are currently spending.
Abstract: This paper discusses the applicability of the numerical model for a damage prediction method of the accidental hydrogen explosion occurring in a hydrogen facility. The numerical model was based on an unstructured finite volume method (FVM) code “NuFD/FrontFlowRed”. For simulating unsteady turbulent combustion of leaked hydrogen gas, a combination of Large Eddy Simulation (LES) and a combustion model were used. The combustion model was based on a two scalar flamelet approach, where a G-equation model and a conserved scalar model expressed a propagation of premixed flame surface and a diffusion combustion process, respectively. For validation of this numerical model, we have simulated the previous two types of hydrogen explosion tests. One is open-space explosion test, and the source was a prismatic 5.27 m3 volume with 30% of hydrogen-air mixture. A reinforced concrete wall was set 4 m away from the front surface of the source. The source was ignited at the bottom center by a spark. The other is vented enclosure explosion test, and the chamber was 4.6 m × 4.6 m × 3.0 m with a vent opening on one side. Vent area of 5.4 m2 was used. Test was performed with ignition at the center of the wall opposite the vent. Hydrogen-air mixtures with hydrogen concentrations close to 18% vol. were used in the tests. The results from the numerical simulations are compared with the previous experimental data for the accuracy of the numerical model, and we have verified that the simulated overpressures and flame time-of-arrival data were in good agreement with the results of the previous two explosion tests.
Abstract: Recently, traffic monitoring has attracted the attention
of computer vision researchers. Many algorithms have been
developed to detect and track moving vehicles. In fact, vehicle
tracking in daytime and in nighttime cannot be approached with the
same techniques, due to the extreme different illumination conditions.
Consequently, traffic-monitoring systems are in need of having a
component to differentiate between daytime and nighttime scenes. In
this paper, a HSV-based day/night detector is proposed for traffic
monitoring scenes. The detector employs the hue-histogram and the
value-histogram on the top half of the image frame. Experimental
results show that the extraction of the brightness features along with
the color features within the top region of the image is effective for
classifying traffic scenes. In addition, the detector achieves high
precision and recall rates along with it is feasible for real time
applications.
Abstract: The application of recycle waste tires into civil
engineering practices, namely asphalt paving mixtures and cementbased
materials has been gaining ground across the world. This
review summarizes and compares the recent achievements in the area
of plain rubberized concrete (PRC), in details. Different treatment
methods have been discussed to improve the performance of
rubberized Portland cement concrete. The review also includes the
effects of size and amount of tire rubbers on mechanical and
durability properties of PRC. The microstructure behaviour of the
rubberized concrete was detailed.
Abstract: Tourism can do a great deal of good in destinations,
whether it be by bringing economic benefits to local communities,
helping with conservation efforts or in placing a value on aspects of
cultural heritage. As responsive travelers, we must all try to do more
of the good and less of the negative. This is simply description of the
sustainable tourism. This paper aims to set some criteria of successful
sustainable tourism development and then through these criteria
analyzing the development of some resorts in Egypt known as
sustainable resorts. Hence, a comprehensive improvement of the
touristic areas is certainly needed to ensure a successful sustainable
tourism development radiated the sense of uniformity and coherence.
Egypt can benefit from these criteria to develop its resorts in order to
preserve and revitalize its unique natural character and achieve mixed
uses and tourism development.
Abstract: Data fusion technology can be the best way to extract
useful information from multiple sources of data. It has been widely
applied in various applications. This paper presents a data fusion
approach in multimedia data for event detection in twitter by using
Dempster-Shafer evidence theory. The methodology applies a mining
algorithm to detect the event. There are two types of data in the
fusion. The first is features extracted from text by using the bag-ofwords
method which is calculated using the term frequency-inverse
document frequency (TF-IDF). The second is the visual features
extracted by applying scale-invariant feature transform (SIFT). The
Dempster - Shafer theory of evidence is applied in order to fuse the
information from these two sources. Our experiments have indicated
that comparing to the approaches using individual data source, the
proposed data fusion approach can increase the prediction accuracy
for event detection. The experimental result showed that the proposed
method achieved a high accuracy of 0.97, comparing with 0.93 with
texts only, and 0.86 with images only.
Abstract: Nowadays, education cannot be imagined without digital technologies. It broadens the horizons of teaching learning processes. Several universities are offering online courses. For evaluation purpose, e-examination systems are being widely adopted in academic environments. Multiple-choice tests are extremely popular. Moving away from traditional examinations to e-examination, Moodle as Learning Management Systems (LMS) is being used. Moodle logs every click that students make for attempting and navigational purposes in e-examination. Data mining has been applied in various domains including retail sales, bioinformatics. In recent years, there has been increasing interest in the use of data mining in e-learning environment. It has been applied to discover, extract, and evaluate parameters related to student’s learning performance. The combination of data mining and e-learning is still in its babyhood. Log data generated by the students during online examination can be used to discover knowledge with the help of data mining techniques. In web based applications, number of right and wrong answers of the test result is not sufficient to assess and evaluate the student’s performance. So, assessment techniques must be intelligent enough. If student cannot answer the question asked by the instructor then some easier question can be asked. Otherwise, more difficult question can be post on similar topic. To do so, it is necessary to identify difficulty level of the questions. Proposed work concentrate on the same issue. Data mining techniques in specific clustering is used in this work. This method decide difficulty levels of the question and categories them as tough, easy or moderate and later this will be served to the desire students based on their performance. Proposed experiment categories the question set and also group the students based on their performance in examination. This will help the instructor to guide the students more specifically. In short mined knowledge helps to support, guide, facilitate and enhance learning as a whole.
Abstract: In the aviation industry, many faults may occur frequently during the maintenance processes and assembly operations of complex structured aircrafts because of their high dependencies of components. These faults affect the quality of aircraft parts or developed modules adversely. Technical employee requires long time and high labor force while checking the correctness of each component. In addition, the person must be trained regularly because of the ever-growing and changing technology. Generally, the cost of this training is very high. Augmented Reality (AR) technology reduces the cost of training radically and improves the effectiveness of the training. In this study, the usage of AR technology in the aviation industry has been investigated and the effectiveness of AR with heads-up display glasses has been examined. An application has been developed for comparison of production process with AR and manual one.
Abstract: Teaching methods include lectures, workshops and
tutorials for the presentation and discussion of ideas have become out
of date; were developed outside the discipline of architecture from
the college of engineering and do not satisfy the architectural
students’ needs and causes them many difficulties in integrating
structure into their design. In an attempt to improve structure
teaching methods, this paper focused upon proposing a supportive
teaching/learning tool using multi-media applications which seeks to
better meet the architecture student’s needs and capabilities and
improve the understanding and application of basic and intermediate
structural engineering and technology principles. Before introducing
the use of multi-media as a supportive teaching tool, a questionnaire
was distributed to third year students of a structural design course
who were selected as a sample to be surveyed forming a sample of 90
cases. The primary aim of the questionnaire was to identify the
students’ learning style and to investigate whether the selected
method of teaching could make the teaching and learning process
more efficient. Students’ reaction on the use of this method was
measured using three key elements indicating that this method is an
appropriate teaching method for the nature of the students and the
course as well.
Abstract: Green roof system is considered a relatively new
concept in Malaysia even though it has been implemented widely in
the developed countries. Generally, green roofs provide many
benefits such as enhancing aesthetical quality of the built
environment, reduce urban heat island effect, reduce energy
consumption, improve stormwater attenuation, and reduce noise
pollution. A better understanding on the implementation of green roof
system in Malaysia is crucial, as Malaysia’s climate is different if
compared with the climate in temperate countries where most of the
green roof studies have been conducted. This study has concentrated
on the technical aspect of green roof system which focuses on i) types
of plants and method of planting; ii) engineering design for green
roof system; iii) its hydrological performance on reducing stormwater
runoff; and iv) benefits of green roofs with respect to energy.
Literature review has been conducted to identify the development and
obstacles associated with green roofs systems in Malaysia. The study
had identified the challenges and potentials of green roofs
development in Malaysia. This study also provided the
recommendations on standard design and strategies on the
implementation of green roofs in Malaysia in the near future.
Abstract: For several hundred years, the design of railway tracks
has practically remained unchanged. Traditionally, rail tracks are
placed on a ballast layer due to several reasons, including economy,
rapid drainage, and high load bearing capacity. The primary function
of ballast is to distributing dynamic track loads to sub-ballast and
subgrade layers, while also providing lateral resistance and allowing
for rapid drainage. Upon repeated trainloads, the ballast becomes
fouled due to ballast degradation and the intrusion of fines which
adversely affects the strength and deformation behaviour of ballast.
This paper presents the use of three-dimensional discrete element
method (DEM) in studying the shear behaviour of the fouled ballast
subjected to direct shear loading. Irregularly shaped particles of
ballast were modelled by grouping many spherical balls together in
appropriate sizes to simulate representative ballast aggregates. Fouled
ballast was modelled by injecting a specified number of miniature
spherical particles into the void spaces. The DEM simulation
highlights that the peak shear stress of the ballast assembly decreases
and the dilation of fouled ballast increases with an increase level of
fouling. Additionally, the distributions of contact force chain and
particle displacement vectors were captured during shearing progress,
explaining the formation of shear band and the evolutions of
volumetric change of fouled ballast.
Abstract: The aim of irrigation is to recharge the available water
in the soil. Quality of irrigation water is essential for the yield and
quality of crops produced, maintenance of soil productivity and
protection of the environment. The analysis of irrigation water arises
as a need to know the impact of irrigation water on the yield of crops,
the effect, and the necessary control measures to rectify the effect of
this for optimum production and yield of crops. This study was conducted to assess the quality of irrigation water
with its performance on crop planted, in Josepdam irrigation scheme
Bacita, Nigeria. Field visits were undertaken to identify and locate
water supply sources and collect water samples from these sources;
X1 Drain, Oshin, River Niger loop and Ndafa. Laboratory
experiments were then undertaken to determine the quality of raw
water from these sources. The analysis was carried for various parameters namely; physical
and chemical analyses after water samples have been taken from four
sources. The samples were tested in laboratory. Results showed that
the raw water sources shows no salinity tendencies with SAR values
less than 1me/l and Ecvaules at Zero while the pH were within the
recommended range by FAO, there are increase in potassium and
sulphate content contamination in three of the location. From this, it
is recommended that there should be proper monitoring of the
scheme by conducting analysis of water and soil in the environment,
preferable test should be carried out at least one year to cover the
impact of seasonal variations and to determine the physical and
chemical analysis of the water used for irrigation at the scheme.
Abstract: Many cluster based routing protocols have been
proposed in the field of wireless sensor networks, in which a group of
nodes are formed as clusters. A cluster head is selected from one
among those nodes based on residual energy, coverage area, number
of hops and that cluster-head will perform data gathering from
various sensor nodes and forwards aggregated data to the base station
or to a relay node (another cluster-head), which will forward the
packet along with its own data packet to the base station. Here a
Game Theory based Diligent Energy Utilization Algorithm (GTDEA)
for routing is proposed. In GTDEA, the cluster head selection is done
with the help of game theory, a decision making process, that selects
a cluster-head based on three parameters such as residual energy
(RE), Received Signal Strength Index (RSSI) and Packet Reception
Rate (PRR). Finding a feasible path to the destination with minimum
utilization of available energy improves the network lifetime and is
achieved by the proposed approach. In GTDEA, the packets are
forwarded to the base station using inter-cluster routing technique,
which will further forward it to the base station. Simulation results
reveal that GTDEA improves the network performance in terms of
throughput, lifetime, and power consumption.
Abstract: In this study, total fatty acid composition of muscle
lipids of Cyprinus carpio L. living in Suğla Dam Lake, Altinapa Dam
Lake, Eğirdir Lake and Burdur Lake were determined using GC.
During this study, for the summer season of July was taken from each
region of the land and they were stored in deep-freeze set to -20
degrees until the analysis date. At the end of the analyses, 30
different fatty acids were found in the composition of Cyprinus
carpio L. which lives in different lakes. Cyprinus carpio Suğla Dam
Lake of polyunsaturated fatty acids (PUFAs), were higher than other
lakes. Cyprinus carpio L. was the highest in the major SFA palmitic
acid. Polyunsaturated fatty acids (PUFA) of carp, the most abundant
fish species in all lakes, were found to be higher than those of
saturated fatty acids (SFA) in all lakes. Palmitic acid was the major
SFA in all lakes. Oleic acid was identified as the major MUFA.
Docosahexaenoic acid (DHA) was the most abundant in all lakes. ω3
fatty acid composition was higher than the percentage of the
percentage ω6 fatty acids in all lake. ω3/ω6 rates of Cyprinus carpio
L. Suğla Dam Lake, Altinapa Dam Lake, Eğirdir Lake and Burdur
Lake, 2.12, 1.19, 2.15, 2.87, and 2.82, respectively. Docosahexaenoic
acid (DHA) was the major PUFA in Eğirdir and Burdur lakes,
whereas linoleic acid (LA) was the major PUFA in Altinapa and
Suğla Dam Lakes. It was shown that the fatty acid composition in the
muscle of carp was significantly influenced by different lakes.
Abstract: Aerobic dance has becoming a popular mode of
exercise especially among women due to its fun nature. With a catchy
music background and joyful dance steps, aerobic dancers would be
able to have fun while sweating out. Depending on its level of
aggressiveness, aerobic may also improve and maintain
cardiorespiratory fitness other than being a great tool for weight loss.
This study intends to prove that aerobic dance activity can bring the
same, if not better impacts on health than other types of
cardiovascular exercise such as jogging and cycling. The objective of
this study was to evaluate and identify the effect of six weeks aerobic
dance on cardiovascular fitness and weight loss among women. This
study, which was held in Seremban Fit Challenge, used a quasiexperimental
design. The subjects selected include a total of 14
women (n = 14) with age (32.4 years old ± 9.1), weight (65.93 kg ±
11.24) and height (165.36 ± 3.46) who joined the Seremban Fit
Challenge Season 13. The subjects were asked to join an aerobic
dance class with a duration of one hour for six weeks in a row. As for
the outcome, cardiovascular fitness was measured with a 1-mile run
test while any changes on weight were measured using the weighing
scale. The result showed that there was a significant difference
between pre and post-test for cardiovascular fitness when p = 0.02
Abstract: This paper describes an ab-initio design, development and calibration results of an Optical Sensor Ground Reaction Force Measurement Platform (OSGRFP) for gait and geriatric studies. The developed system employs an array of FBG sensors to measure the respective ground reaction forces from all three axes (X, Y and Z), which are perpendicular to each other. The novelty of this work is two folded. One is in its uniqueness to resolve the tri axial resultant forces during the stance in to the respective pure axis loads and the other is the applicability of inherently advantageous FBG sensors which are most suitable for biomechanical instrumentation. To validate the response of the FBG sensors installed in OSGRFP and to measure the cross sensitivity of the force applied in other directions, load sensors with indicators are used. Further in this work, relevant mathematical formulations are presented for extracting respective ground reaction forces from wavelength shifts/strain of FBG sensors on the OSGRFP. The result of this device has implications in understanding the foot function, identifying issues in gait cycle and measuring discrepancies between left and right foot. The device also provides a method to quantify and compare relative postural stability of different subjects under test, which has implications in post-surgical rehabilitation, geriatrics and optimizing training protocols for sports personnel.
Abstract: Torrefaction of biomass pellets is considered as a
useful pretreatment technology in order to convert them into a high
quality solid biofuel that is more suitable for pyrolysis, gasification,
combustion, and co-firing applications. In the course of torrefaction,
the temperature varies across the pellet, and therefore chemical
reactions proceed unevenly within the pellet. However, the
uniformity of the thermal distribution along the pellet is generally
assumed. The torrefaction process of a single cylindrical pellet is
modeled here, accounting for heat transfer coupled with chemical
kinetics. The drying sub-model was also introduced. The nonstationary
process of wood pellet decomposition is described by the
system of non-linear partial differential equations over the
temperature and mass. The model captures well the main features of
the experimental data.
Abstract: Medicinal and aromatic plants are promising and are characterized by the biosynthesis of odorous molecules that make up the so-called essential oils (EO), which have long been known for their antiseptic and therapeutic activity in folk medicine. Essential oils have many therapeutic properties. In herbal medicine, they are used for their antiseptic properties against infectious diseases of fungal origin, against dermatophytes, those of bacterial origin. The objective of this study was to evaluate the influence of drying in the shade on the water content and on the content of essential oils extracted from leaves of Eucalyptus camendulensis for better quality control of medicinal and aromatic plants. The water content of the Eucalyptus camendulensis plant material decreases during the drying process. It decreased from 100% to 0.006% for the drying in the shade after ten days. The moisture content is practically constant at the end of the drying period. The drying in the shade increases the concentration of essential oils of Eucalyptus camendulensis. When the leaves of Eucalyptus camendulensis plant are in the shade, the maximum of the essential oil content was obtained on the eighth day, the recorded value was 1.43% ± 0.01%. Beyond these periods, the content continuously drop in before stabilizing. The optimum drying time is between 6 and 9 days.
Abstract: This paper aims to link together the concepts of job
satisfaction, work engagement, trust, job meaningfulness and loyalty
to the organisation focusing on specific type of employment –
academic jobs. The research investigates the relationships between
job satisfaction, work engagement and loyalty as well as the impact
of trust and job meaningfulness on the work engagement and loyalty.
The survey was conducted in one of the largest Latvian higher
education institutions and the sample was drawn from academic staff
(n=326). Structured questionnaire with 44 reflective type questions
was developed to measure the constructs. Data was analysed using
SPSS and Smart-PLS software. Variance based structural equation
modelling (PLS-SEM) technique was used to test the model and to
predict the most important factors relevant to employee engagement
and loyalty. The first order model included two endogenous
constructs (loyalty and intention to stay and recommend to work in
this organisation, and employee engagement), as well as six
exogenous constructs (feeling of fair treatment and trust in
management; career growth opportunities; compensation, pay and
benefits; management; colleagues and teamwork; and finally job
meaningfulness). Job satisfaction was developed as second order
construct and both: first and second order models were designed for
data analysis. It was found that academics are more engaged than
satisfied with their work and main reason for that was found to be job
meaningfulness, which is significant predictor for work engagement,
but not for job satisfaction. Compensation is not significantly related
to work engagement, but only to job satisfaction. Trust was not
significantly related neither to engagement, nor to satisfaction,
however, it appeared to be significant predictor of loyalty and
intentions to stay with the University. Paper revealed academic jobs
as specific kind of employment where employees can be more
engaged than satisfied and highlighted the specific role of job
meaningfulness in the University settings.