Abstract: This work consists of a numerical simulation of
convective heat transfer in a vertical plane channel filled with a heat
generating porous medium, in the absence of local thermal
equilibrium. The walls are maintained to a constant temperature and
the inlet velocity is uniform. The dynamic range is described by the
Darcy-Brinkman model and the thermal field by two energy
equations model. A dimensionless formulation is developed for
performing a parametric study based on certain dimensionless groups
such as, the Biot interstitial number, the thermal conductivity ratio
and the volumetric heat generation, q '''. The governing equations are
solved using the finite volume method, gave rise to a multitude of
results concerning in particular the thermal field in the porous
channel and the existence or not of the local thermal equilibrium.
Abstract: Nowadays, the use of renewable energy sources has been increasingly great because of the cost increase and public demand for clean energy sources. One of the fastest growing sources is wind energy. In this paper, Wind Diesel Hybrid System (WDHS) comprising a Diesel Generator (DG), a Wind Turbine Generator (WTG), the Consumer Load, a Battery-based Energy Storage System (BESS), and a Dump Load (DL) is used. Voltage is controlled by Diesel Generator; the frequency is controlled by BESS and DL. The BESS elimination is an efficient way to reduce maintenance cost and increase the dynamic response. Simulation results with graphs for the frequency of Power System, active power, and the battery power are presented for load changes. The controlling parameters are optimized by using Imperialist Competitive Algorithm (ICA). The simulation results for the BESS/no BESS cases are compared. Results show that in no BESS case, the frequency control is more optimal than the BESS case by using ICA.
Abstract: In this paper, the dependence of soliton pulses with
respect to phase in a 10Gbps, single channel, dispersion
uncompensated telecommunication system was studied. The
characteristic feature of periodic soliton interaction was noted at the
Interaction point (I=6202.5Km) in one collision length of L=12405.1
Km. The interaction point is located for 10Gbps system with an
initial relative spacing (qo) of soliton as 5.28 using Perturbation
theory. It is shown that, when two in-phase solitons are launched,
they interact at the point I=6202.5 Km, but the interaction could be
restricted with introduction of different phase initially. When the
phase of the input solitons increases, the deviation of soliton pulses at
the ‘I’ also increases. We have successfully demonstrated this effect
in a telecommunication set-up in terms of Quality factor (Q), where
the Q=0 for in-phase soliton. The Q was noted to be 125.9, 38.63,
47.53, 59.60, 161.37, and 78.04 for different phases such as 10o, 20o,
30o, 45o, 60o and 90o degrees respectively at Interaction point (I).
Abstract: Any variation in environmental characteristics of
geomorphosites would lead to destabilisation of their geotouristic
values all around the planet. The Urmia lake, with an area of
approximately 5,500 km2 and a catchment area of 51,876 km2, and to
which various reasons over time, especially in the last fifty years
have seen a sharp decline and have decreased by about 93 % in two
recent decades. These variations are not only driving significant
changes in the morphology and ecology of the present lake
landscape, but at the same time are shaping newly formed
morphologies, which vanished some valuable geomorphosites or
develop into smaller geomorphosites with significant value from a
scientific and cultural point of view. This paper analyses and
discusses features and evolution in several representative coastal and
island geomorphosites. For this purpose, a total of 23 geomorphosites
were studied in two data series (1963 and 2015) and the respective
data were compared and analysed. The results showed, the total loss
in geomorphosites area in a half century amounted to a loss of more
than 90% of the valuable geomorphosites. Moreover, the comparison
between the mean yearly value of coastal area lost over the entire
period and the yearly average calculated for the shorter period (1998-
2014) clearly indicates a pattern of acceleration. This acceleration in
the rate of reduction in lake area was seen in most of the southern
half of the lake. In the region as well, the general water-level falling
is not only causing the loss of a significant water resource, which is
followed by major impact on regional ecosystems, but is also driving
the most marked recent (last century) changes in the geotouristic
landscapes. In fact, the disappearance of geomorphosites means the
loss of tourism phenomenon. In this context attention must be paid to
the question of conservation. The action needed to safeguard
geomorphosites includes: 1) Preventive action, 2) Corrective action,
and 3) Sharing knowledge.
Abstract: Intermetallic materials are among advanced
technology materials that have outstanding mechanical and physical
properties for high temperature applications. Especially creep
resistance, low density and high hardness properties stand out in such
intermetallics. The microstructure, mechanical properties of %88Ni-
%10Cr and %2Mn powders were investigated using specimens
produced by tube furnace sintering at 900-1300°C temperature. A
composite consisting of ternary additions, a metallic phase, Fe, Cr
and Mn have been prepared under Ar shroud and then tube furnace
sintered. XRD, SEM (Scanning Electron Microscope), were
investigated to characterize the properties of the specimens.
Experimental results carried out for composition %88Ni-%10Cr and
%2Mn at 1300°C suggest that the best properties as 138,80HV and
6,269/cm3 density were obtained at 1300°C.
Abstract: Here, we study the characteristic feature of
conventional (ON-OFF keying) and soliton based transmission
system. We consider 20Gbps transmission system implemented with
Conventional Single Mode Fiber (C-SMF) to examine the role of
Gaussian pulse which is the characteristic of conventional
propagation and Hyperbolic-secant pulse which is the characteristic
of soliton propagation in it. We note the influence of these pulses
with respect to different dispersion lengths and soliton period in
conventional and soliton system respectively and evaluate the system
performance in terms of Quality factor. From the analysis, we could
prove that the soliton pulse has the consistent performance even for
long distance without dispersion compensation than the conventional
system as it is robust to dispersion. For the length of transmission of
200Km, soliton system yielded Q of 33.958 while the conventional
system totally exhausted with Q=0.
Abstract: As the trend in automotive technology is fast moving
towards hybridization and electrification to curb emissions as well as
to improve the fuel efficiency, air-conditioning systems in passenger
cars have not caught up with this trend and still remain as the major
energy consumers amongst others. Adsorption based air-conditioning
systems, e.g. with silica-gel water pair, which are already in use for
residential and commercial applications, are now being considered as
a technology leap once proven feasible for the passenger cars. In this
paper we discuss a methodology, challenges and feasibility of
implementing an adsorption based air-conditioning system in a
passenger car utilizing the exhaust waste heat. We also propose an
optimized control strategy with interfaces to the engine control unit
of the vehicle for operating this system with reasonable efficiency
supported by our simulation and validation results in a prototype
vehicle, additionally comparing to existing implementations,
simulation based as well as experimental. Finally we discuss the
influence of start-stop and hybrid systems on the operation strategy of
the adsorption air-conditioning system.
Abstract: The effects of the pumping wavelength and their power
on the gain flattening of a fiber Raman amplifier (FRA) are
investigated. The multi-wavelength pumping scheme is utilized to
achieve gain flatness in FRA. It is proposed that gain flatness
becomes better with increase in number of pumping wavelengths
applied. We have achieved flat gain with 0.27 dB fluctuation in a
spectral range of 1475-1600 nm for a Raman fiber length of 10 km by
using six pumps with wavelengths with in the 1385-1495 nm interval.
The effect of multi-wavelength pumping scheme on gain saturation in
FRA is also studied. It is proposed that gain saturation condition gets
improved by using this scheme and this scheme is more useful for
higher spans of Raman fiber length.
Abstract: Activated carbon is an amorphous carbon chain which
has extremely extended surface area. High surface area of activated
carbon is due to the porous structure. Activated carbon, using a
variety of materials such as coal and cellulosic materials; can be
obtained by both physical and chemical methods. The prepared
activated carbon can be used for decolorize, deodorize and also can
be used for removal of organic and non-organic pollution. In this
study, pomegranate peel was subjected to 800W microwave power
for 1 to 4 minutes. Also fresh pomegranate peel was used for the
reference material. Then ZnCl2 was used for the chemical activation
purpose. After the activation process, activated pomegranate peels
were used for the adsorption of Zn metal (40 ppm) in the waste water.
As a result of the adsorption experiments, removal of heavy metals
ranged from 89% to 85%.
Abstract: Nanofibers are effective materials which have
frequently been investigated to produce high quality air filters. As an
environmental approach our aim is to achieve nanofibers by melting.
In spun-bond systems extruder, spin-pump, nozzle package and
attenuator are used. Molten polymer which flows from extruder is
made steady by spin-pump. Regular melt passes through nozzle holes
and forms fibers under high pressure. The fibers pulled from nozzle
are shrunk to micron size by an attenuator; after solidification, they
are collected on a conveyor. In this research different designs of
attenuator system have been studied; and also CFD analysis has been
done on these different designs. Afterwards, one of these designs
tested and finally some optimizations have been done to reduce
pressure loss and increase air velocity.
Abstract: Customer churn prediction is one of the most useful
areas of study in customer analytics. Due to the enormous amount
of data available for such predictions, machine learning and data
mining have been heavily used in this domain. There exist many
machine learning algorithms directly applicable for the problem of
customer churn prediction, and here, we attempt to experiment on
a novel approach by using a cognitive learning based technique in
an attempt to improve the results obtained by using a combination
of supervised learning methods, with cognitive unsupervised learning
methods.
Abstract: Bir El Djir is an important coastal township in Oran
department, located at 450 Km far away from Algiers on northwest of
Algeria. In this coastal area, the urban sprawl is one of the main
problems that reduce the limited highly fertile land. So, using the
remote sensing and GIS technologies have shown their great
capabilities to solve many earth resources issues.
The aim of this study is to produce land use and cover map for the
studied area at varied periods to monitor possible changes that may
occurred, particularly in the urban areas and subsequently predict
likely changes. For this, two spatial images SPOT and Landsat
satellites from 1987 and 2014 respectively were used to assess the
changes of urban expansion and encroachment during this period
with photo-interpretation and GIS approach.
The results revealed that the town of Bir El Djir has shown a
highest growth rate in the period 1987-2014 which is 1201.5 hectares
in terms of area. These expansions largely concern the new real estate
constructions falling within the social and promotional housing
programs launched by the government.
The most urban expansion is characterized by the new
construction in the form of spontaneous or peripheral precarious
habitat, but also unstructured slums settled especially in the
southeastern part of town.
Abstract: As the economies of other countries in the
Mediterranean Basin, the tourism sector in our country has a high
denominator in economics. Tourism businesses, which are building
blocks of tourism, sector faces with a variety of problems during their
activities. These problems faced make business efficiency and
competition conditions of the businesses difficult. Most of the
problems faced by the tourism businesses and the information of
consumers about consumers’ rights were used in this study, which is
conducted to determine the problems of tourism businesses in the
Central Anatolia Region. It is aimed to contribute the awareness of
staff and executives working at tourism sector and to attract attention
of businesses active concurrently with tourism sector and legislators.
Abstract: The objective of this study was to assess whether
living in proximity to a roofing fiber cement factory in southern
Thailand was associated with physical, mental, social, and spiritual
health domains measured in a self-reported health risk assessment
(HRA) questionnaire. A cross-sectional study was conducted among
community members divided into two groups: near population (living
within 0-2km of factory) and far population (living within 2-5km of
factory) (N=198). A greater proportion of those living far from the
factory (65.34%) reported physical health problems than the near
group (51.04%) (p =0.032). This study has demonstrated that the near
population group had higher proportion of participants with positive
ratings on mental assessment (30.34%) and social health impacts
(28.42%) than far population group (10.59% and 16.67%,
respectively) (p
Abstract: The organizations in the knowledge economy era have
recognized the importance of building knowledge assets for
sustainable growth and development. In comparison to other
industries, Information Technology (IT) enterprises, holds an edge in
developing an effective Knowledge Management (KM) programmethanks
to their in-house technological abilities. This paper tries to
study the various knowledge based incentive programmes and its
effect on Knowledge Sharing and Learning in the context of the
Indian IT sector. A conceptual model is developed linking KM
Incentives, Knowledge Sharing and Learning. A questionnaire study
is conducted to collect primary data from the knowledge workers of
the IT organizations located in India. The data was analysed using
Structural Equation Modeling using Partial Least Square method. The
results show a strong influence of knowledge management incentives
on knowledge sharing and an indirect influence on learning.
Abstract: In this investigation, we have evaluated the effects of
arsenic trioxide on hepatic function in pregnant and lactating Swiss
albino mice and their suckling pups. Experiments were carried out on
female mice given 175 ppm As2O3 in their drinking water from the
14th day of pregnancy until day 14 after delivery. Our results showed
a significant decrease in plasma levels of total protein and albumin,
cholesterol and triglyceride in As2O3 treated mice and their pups. The
hyperbilirubinemia and the increased plasma total alkaline
phosphatase activity suggested the presence of cholestasis.
Transaminase activities as well as lactate deshydrogenase activity in
plasma, known as biomarkers of hepatocellular injury, were elevated
indicating hepatic cells’ damage after treatment with As2O3.
Exposure to arsenic led to an increase of liver thiobarbituric acid
reactive substances level along with a concomitant decrease in the
activities of superoxide dismutase, catalase and glutathione
peroxidase and in glutathione.
Abstract: Generally the natural environment is made up of air,
water and soil. The release of emission of industrial waste into
anyone of the components of the environment causes pollution.
Industrial pollution significantly threatens the inherent right of
people, to the enjoyment of a safe and secure environment. The aim
of this paper is to assess the effect of environmental pollution and
health risks of residents living near Ewekoro cement factory. The
research made use of IKONOS imagery for Geographical
Information System (GIS) to buffer and extract buildings that are less
than 1km to the factory, within 1km to 5km and above 5km to the
factory. Also questionnaire was used to elicit information on the
socio-economic factors, effect of environmental pollution on
residents and measures adopted to control industrial pollution on the
residents. Findings show that most buildings that fall between less
than 1km and 1km to 5km to the factory have high health risk in the
study area. The study recommended total relocation for the residents
of the study area to reduce health risk problems.
Abstract: The California Bearing Ratio (CBR) has been
acknowledged as an important parameter to characterize the bearing
capacity of earth structures, such as earth dams, road embankments,
airport runways, bridge abutments and pavements. Technically, the
CBR test can be carried out in the laboratory or in the field. The CBR
test is time-consuming and is infrequently performed due to the
equipment needed and the fact that the field moisture content keeps
changing over time. Over the years, many correlations have been
developed for the prediction of CBR by various researchers,
including the dynamic cone penetrometer, undrained shear strength
and Clegg impact hammer. This paper reports and discusses some of
the results from a study on the prediction of CBR. In the current
study, the CBR test was performed in the laboratory on some finegrained
subgrade soils collected from various locations in Victoria.
Based on the test results, a satisfactory empirical correlation was
found between the CBR and the physical properties of the
experimental soils.
Abstract: Leukaemia is a blood cancer disease that contributes
to the increment of mortality rate in Malaysia each year. There are
two main categories for leukaemia, which are acute and chronic
leukaemia. The production and development of acute leukaemia cells
occurs rapidly and uncontrollable. Therefore, if the identification of
acute leukaemia cells could be done fast and effectively, proper
treatment and medicine could be delivered. Due to the requirement of
prompt and accurate diagnosis of leukaemia, the current study has
proposed unsupervised pixel segmentation based on clustering
algorithm in order to obtain a fully segmented abnormal white blood
cell (blast) in acute leukaemia image. In order to obtain the
segmented blast, the current study proposed three clustering
algorithms which are k-means, fuzzy c-means and moving k-means
algorithms have been applied on the saturation component image.
Then, median filter and seeded region growing area extraction
algorithms have been applied, to smooth the region of segmented
blast and to remove the large unwanted regions from the image,
respectively. Comparisons among the three clustering algorithms are
made in order to measure the performance of each clustering
algorithm on segmenting the blast area. Based on the good sensitivity
value that has been obtained, the results indicate that moving kmeans
clustering algorithm has successfully produced the fully
segmented blast region in acute leukaemia image. Hence, indicating
that the resultant images could be helpful to haematologists for
further analysis of acute leukaemia.
Abstract: Photonic Crystal Fibers (PCFs) can be used in optical
communications as transmission lines. For this reason, the PCFs with
low confinement loss, low chromatic dispersion, and low nonlinear
effects are highly suitable transmission media. In this paper, we
introduce a new design of index-guiding nanostructured photonic
crystal fiber (IG-NPCF) with ultra-low chromatic dispersion, low
nonlinearity effects, and low confinement loss. Relatively low
dispersion is achieved in the wavelength range of 1200 to 1600nm
using the proposed design. According to the new structure of
nanostructured PCF presented in this study, the chromatic dispersion
slope is -30(ps/km.nm) and the confinement loss reaches below 10-7
dB/km. While in the wavelength range mentioned above at the same
time an effective area of more than 50.2μm2 is obtained.