Abstract: In the present research, the titanium-catalyzed
ethylene dimerization and more specifically, the concomitant byproducts
and polymer formation have been studied in the presence of 2,5-dimethoxytetrahydrofuran as an electron donor compound in the
combination with triethylaluminium (TEA) as activator. Then, we
added ethylene chlorobromide as a new efficient promoter to the
relevant catalyst system. Finally, the behavior of novel homogeneous
[Titanium tetrabutoxide (Ti(OC4H9)4)/2,5-dimethoxytetrahydrofuran/
TEA/ethylene chlorobromide] was investigated in the various
operating conditions for the optimum production of 1-butene. In the
optimum conditions, a very high ethylene conversion (almost 90.77
%), a relative high selectivity to 1-butene (79.00 %), yield of reaction equal to 71.70 % and a significant productivity (turnover frequency
equal to 1370 h-1) were achieved.
Abstract: This paper evaluates the performance of a novel
algorithm for tracking of a mobile node, interms of execution time
and root mean square error (RMSE). Particle Filter algorithm is used
to track the mobile node, however a new technique in particle filter
algorithm is also proposed to reduce the execution time. The
stationary points were calculated through trilateration and finally by
averaging the number of points collected for a specific time, whereas
tracking is done through trilateration as well as particle filter
algorithm. Wi-Fi signal is used to get initial guess of the position of
mobile node in x-y coordinates system. Commercially available
software “Wireless Mon" was used to read the WiFi signal strength
from the WiFi card. Visual Cµ version 6 was used to interact with
this software to read only the required data from the log-file
generated by “Wireless Mon" software. Results are evaluated through
mathematical modeling and MATLAB simulation.
Abstract: This paper presents the design, development and characterization of contractile water jet thruster (CWJT) for mini underwater robot. Instead of electric motor, this CWJT utilizes the Ionic Polymer Metal Composite (IPMC) as the actuator to generate the water jet. The main focus of this paper is to analyze the conceptual design of the proposed CWJT which would determine the thrust force value, jet flow behavior and actuator’s stress. Those thrust force and jet flow studies were carried out using Matlab/Simscape simulation software. The actuator stress had been analyzed using COSMOS simulation software. The results showed that there was no significant change for jet velocity at variable cross sectional nozzle area. However, a significant change was detected for jet velocity at different nozzle cross sectional area ratio which was up to 37%. The generated thrust force has proportional relation to the nozzle cross sectional area.
Abstract: Carriers scattering in the inversion channel of n-
MOSFET dominates the drain current. This paper presents an effective
electron mobility model for the pocket implanted nano scale
n-MOSFET. The model is developed by using two linear pocket
profiles at the source and drain edges. The channel is divided into
three regions at source, drain and central part of the channel region.
The total number of inversion layer charges is found for these three
regions by numerical integration from source to drain ends and the
number of depletion layer charges is found by using the effective
doping concentration including pocket doping effects. These two
charges are then used to find the effective normal electric field,
which is used to find the effective mobility model incorporating the
three scattering mechanisms, such as, Coulomb, phonon and surface
roughness scatterings as well as the ballistic phenomena for the
pocket implanted nano-scale n-MOSFET. The simulation results show
that the derived mobility model produces the same results as found
in the literatures.
Abstract: This work concerns the measurements of a Bulk
Acoustic Waves (BAW) emission filter S parameters and compare
with prototypes simulated types. Thanks to HP-ADS, a co-simulation
of filters- characteristics in a digital radio-communication chain is
performed. Four cases of modulation schemes are studied in order to
illustrate the impact of the spectral occupation of the modulated
signal. Results of simulations and co-simulation are given in terms of
Error Vector Measurements to be useful for a general sensibility
analysis of 4th/3rd Generation (G.) emitters (wideband QAM and
OFDM signals)
Abstract: The spreading characteristics of acoustically excited
swirling double-concentric jets were studied experimentally. The
central jet was acoustically excited at low and high pulsation
intensities. A smoke wire flow visualization and a hot-wire
anemometer velocity measurement results show that excitation forces
a vortex ring to roll-up from the edge of the central tube during each
excitation period. At low pulsation intensities, the vortex ring evolves
downstream, and eventually breaks up into turbulent eddies. At high
pulsation intensities, the primary vortex ring evolves and a series of
trailing vortex rings form during the same period of excitation. The
trailing vortex rings accelerate while evolving downstream and
overtake the primary vortex ring within the same cycle. In the
process, the primary vortex ring becomes unstable and breaks up
early. The effect of the fast traveling trailing vortex rings combined
with the swirl motion of the annular flow improve jet spreading
compared with the naturally evolving jets.
Abstract: Citizens are increasingly are provided with choice and
customization in public services and this has now also become a key
feature of higher education in terms of policy roll-outs on personal
development planning (PDP) and more generally as part of the
employability agenda. The goal here is to transform people, in this
case graduates, into active, responsible citizen-workers. A key part of
this rhetoric and logic is the inculcation of graduate attributes within
students. However, there has also been a concern with the issue of
student lack of engagement and perseverance with their studies. This
paper sets out to explore some of these conceptions that link graduate
attributes with citizenship as well as the notion of how identity is
forged through the higher education process. Examples are drawn
from a quality enhancement project that is being operated within the
context of the Scottish higher education system. This is further
framed within the wider context of competing and conflicting
demands on higher education, exacerbated by the current worldwide
economic climate. There are now pressures on students to develop
their employability skills as well as their capacity to engage with
global issues such as behavioural change in the light of
environmental concerns. It is argued that these pressures, in effect,
lead to a form of personalization that is concerned with how
graduates develop their sense of identity as something that is
engineered and re-engineered to meet these demands.
Abstract: We have applied new accelerated algorithm for linear
discriminate analysis (LDA) in face recognition with support vector
machine. The new algorithm has the advantage of optimal selection
of the step size. The gradient descent method and new algorithm has
been implemented in software and evaluated on the Yale face
database B. The eigenfaces of these approaches have been used to
training a KNN. Recognition rate with new algorithm is compared
with gradient.
Abstract: Online discussions are an important component of
both blended and online courses. This paper examines the varieties of
online discussions and the perils, pitfalls and possibilities of this
rather new technological tool for enhanced learning. The discussion
begins with possible perils and pitfalls inherent in this educational
tool and moves to a consideration of the advantages of the varieties
of online discussions feasible for use in teacher education programs.
Abstract: The production and consumption of natural gas is on
the rise throughout the world as a result of its wide availability, ease
of transportation, use and clean-burning characteristics. The chief use
of ethane is in the chemical industry in the production of Ethene
(ethylene) by steam cracking. In this simulation, obtained ethane
recovery percent based on Gas sub-cooled process (GSP) is 99.9 by
mole that is included 32.1% by using de-methanizer column and
67.8% by de-ethanizer tower. The outstanding feature of this process
is the novel split-vapor concept that employs to generate reflux for
de-methanizer column. Remain amount of ethane in export gas cause
rise in gross heating value up to 36.66 MJ/Nm3 in order to use in
industrial and household consumptions.
Abstract: The quality improvements of the environmental
elements could increase the recreational opportunities in a certain
area (destination). The technique of the need for recreation focuses
on choosing certain destinations for recreational purposes. The basic
exchange taken into consideration is the one between the satisfaction
gained after staying in that area and the value expressed in money
and time allocated. The number of tourists in the respective area, the
duration of staying and the money spent including transportation
provide information on how individuals rank the place or certain
aspects of the area (such as the quality of the environmental
elements).
For the statistical analysis of the environmental benefits offered by
an area through the need of recreation technique, the following stages
are suggested:
- characterization of the reference area based on the
statistical variables considered;
- estimation of the environmental benefit through
comparing the reference area with other similar areas
(having the same environmental characteristics), from
the perspective of the statistical variables considered.
The model compared in recreation technique faced with a series of
difficulties which refers to the reference area and correct
transformation of time in money.
Abstract: This paper proposes rough set models with three
different level knowledge granules in incomplete information system
under tolerance relation by similarity between objects according to
their attribute values. Through introducing dominance relation on the
discourse to decompose similarity classes into three subclasses: little
better subclass, little worse subclass and vague subclass, it dismantles
lower and upper approximations into three components. By using
these components, retrieving information to find naturally hierarchical
expansions to queries and constructing answers to elaborative queries
can be effective. It illustrates the approach in applying rough set
models in the design of information retrieval system to access different
granular expanded documents. The proposed method enhances rough
set model application in the flexibility of expansions and elaborative
queries in information retrieval.
Abstract: The present research focus on the processing of mullite-based ceramics from oil refinery industrial wastes and byproducts of agricultural industry and on the investigating of silane modified surface of ceramics. Two waste products were used as initial material – waste aluminum oxide and waste rice husk. The burning - out additives used were waste rise husk. It is known that the oxide ceramics surface is hydrophilic due to the presence of – OH groups in it. The nature of ceramic surface regarding permeation of water and hydrocarbons can be changed by further treatment with silanes. The samples were studied mainly by X-ray analysis, FT-IR absorbance measurements and microscopic analysis. The X-ray analyses showed the phase composition depends on the firing temperature and on the purity of the starting alumina. Two kind of silanes were used for the transformation of surface from hydrophilic to hydrophobic – trimethoxymethylsilane (TMMS) and trimethylclorsilane (TMCS).
Abstract: A pilot plant for continuous flow microwave-assisted
chemical reaction combined with microreactors was developed and
water heating tests were conducted for evaluation of the developed
plant. We developed a microwave apparatus having a single
microwave generator that can heat reaction solutions in four reaction
fields simultaneously in order to increase throughput. We also
designed a four-branch waveguide using electromagnetic simulation,
and found that the transmission efficiency at 99%. Finally, we
developed the pilot plant using the developed microwave apparatus
and conducted water heating tests. The temperatures in the respective
reaction fields were controlled within ±1.1 K at 353.2 K. Moreover,
the energy absorption rates by the water were about 90% in the
respective reaction fields, whereas the energy absorption rate was
about 40% when 100 cm3 of water was heated by a commercially
available multimode microwave chemical reactor.
Abstract: The flow field within the combustor of scramjet
engine is very complex and poses a considerable challenge in the
design and development of a supersonic combustor with an optimized
geometry. In this paper comprehensive numerical studies on flow
field characteristics of different cavity based scramjet combustors
with transverse injection of hydrogen have been carried out for both
non-reacting and reacting flows. The numerical studies have been
carried out using a validated 2D unsteady, density based 1st-order
implicit k-omega turbulence model with multi-component finite rate
reacting species. The results show a wide variety of flow features
resulting from the interactions between the injector flows, shock
waves, boundary layers, and cavity flows. We conjectured that an
optimized cavity is a good choice to stabilize the flame in the
hypersonic flow, and it generates a recirculation zone in the scramjet
combustor. We comprehended that the cavity based scramjet
combustors having a bearing on the source of disturbance for the
transverse jet oscillation, fuel/air mixing enhancement, and flameholding
improvement. We concluded that cavity shape with
backward facing step and 45o forward ramp is a good choice to get
higher temperatures at the exit compared to other four models of
scramjet combustors considered in this study.
Abstract: An approach is offered for more precise definition of base lines- borders in handwritten cursive text and general problems of handwritten text segmentation have also been analyzed. An offered method tries to solve problems arose in handwritten recognition with specific slant or in other words, where the letters of the words are not on the same vertical line. As an informative features, some recognition systems use ascending and descending parts of the letters, found after the word-s baseline detection. In such recognition systems, problems in baseline detection, impacts the quality of the recognition and decreases the rate of the recognition. Despite other methods, here borders are found by small pieces containing segmentation elements and defined as a set of linear functions. In this method, separate borders for top and bottom border lines are found. At the end of the paper, as a result, azerbaijani cursive handwritten texts written in Latin alphabet by different authors has been analyzed.
Abstract: Bubble generation was observed using a high-speed
camera in subcooled flow boiling at low void fraction. Constant heat
flux was applied on one side of an upward rectangular channel to
make heated test channel. Water as a working fluid from high
subcooling to near saturation temperature was injected step by step to
investigate bubble behavior during void development. Experiments
were performed in two different pressures condition close to 2bar and
4bar. It was observed that in high subcooling when boiling was
commenced, bubble after nucleation departed its origin and slid
beside heated surface. In an observation window mean release
frequency of bubble fb,mean, nucleation site Ns and mean bubble
volume Vb,mean in each step of experiments were measured to
investigate wall vaporization rate. It was found that in proximity of
PNVG vaporization rate was increased significantly in compare with
condensation rate which remained in low value.
Abstract: Low-carbon economy means the energy conservation and emission reduction. How to measure and evaluate the regional low-carbon economy is an important problem which should be solved immediately. This paper proposed the eco-efficiency ratio based on the ecological efficiency to evaluate the current situation of the low-carbon economy in Jiangsu province and to analyze the efficiency of the low-carbon economy in Jiangsu and other provinces, compared both advantages and disadvantages. And then this paper put forward some advices for the government to formulate the correct development policy of low-carbon economy, to improve the technology innovation capacity and the efficiency of resource allocation.
Abstract: Shirvan is located in plain in Northern Khorasan province north east of Iran and has semiarid to temperate climate. To investigate the annual changes in some qualitative parameters such as electrical conductivity, total dissolved solids and chloride concentrations which have increased during ten continuous years. Fourteen groundwater sources including deep as well as semi-deep wells were sampled and were analyzed using standard methods. The trends of obtained data were analyzed during these years and the effects of different factors on the changes in electrical conductivity, concentration of chloride and total dissolved solids were clarified. The results showed that the amounts of some qualitative parameters have been increased during 10 years time which has led to decrease in water quality. The results also showed that increased in urban populations as well as extensive industrialization in the studied area are the most important reasons to influence underground water quality. Furthermore decrease in water quantity is also evident due to more water utilization and occurrence of recent droughts in the region during recent years.
Abstract: In this paper, we propose an approach for the classification of fingerprint databases. It is based on the fact that a fingerprint image is composed of regular texture regions that can be successfully represented by co-occurrence matrices. So, we first extract the features based on certain characteristics of the cooccurrence matrix and then we use these features to train a neural network for classifying fingerprints into four common classes. The obtained results compared with the existing approaches demonstrate the superior performance of our proposed approach.