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: The direct sewage sludge application is a relative
cheap method for their liquidation. In the past heavy metal contents
increase in soils treated with sewage sludge was observed. In 2003
there was acceptance on act n.188/2003 about sewage sludge
application on soils. The basic philosophy of act is a safety of the
environmental proof of sludge application on soils. The samples of
soils from wastewater treatment plant (WTP) Poprad (35) and WTP
Michalovce (33 samples) were analyzed which were chosen for
sludge application on soils. According to the results only 14 areas for
Poprad and 25 areas for Michalovce are suitable for sludge
application according to act No. 188/2003. The application dose of
sludge was calculated 50 t.ha-1 or 75 t. ha-1 once in 5 years to ensure
that heavy metal contents in treated soils will be kept.
Abstract: At the end of the 20th century it was actual the
development of transport corridors and the improvement of their
technical parameters. With this purpose, many countries and Georgia
among them manufacture to construct new highways, railways and
also reconstruction-modernization of the existing transport
infrastructure. It is necessary to explore the artificial structures
(bridges and tunnels) on the existing tracks as they are very old.
Conference report includes the peculiarities of reconstruction of
tunnels, because we think that this theme is important for the
modernization of the existing road infrastructure. We must remark
that the methods of determining mining pressure of tunnel
reconstructions are worked out according to the jobs of new tunnels
but it is necessary to foresee additional mining pressure which will be
formed during their reconstruction. In this report there are given the
methods of figuring the additional mining pressure while
reconstruction of tunnels, there was worked out the computer
program, it is determined that during reconstruction of tunnels the
additional mining pressure is 1/3rd of main mining pressure.
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 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: 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: This paper deals with the project selection problem. Project selection problem is one of the problems arose firstly in the field of operations research following some production concepts from primary product mix problem. Afterward, introduction of managerial considerations into the project selection problem have emerged qualitative factors and criteria to be regarded as well as quantitative ones. To overcome both kinds of criteria, an analytic network process is developed in this paper enhanced with fuzzy sets theory to tackle the vagueness of experts- comments to evaluate the alternatives. Additionally, a modified version of Least-Square method through a non-linear programming model is augmented to the developed group decision making structure in order to elicit the final weights from comparison matrices. Finally, a case study is considered by which developed structure in this paper is validated. Moreover, a sensitivity analysis is performed to validate the response of the model with respect to the condition alteration.
Abstract: This paper discusses the development of wireless
structure control of an induction motor scalar drives. This was
realised up on the wireless WiFi networks. This strategy of control is
ensured by the use of Wireless ad hoc networks and a virtual network
interface based on VNC which is used to make possible to take the
remote control of a PC connected on a wireless Ethernet network.
Verification of the proposed strategy of control is provided by
experimental realistic tests on scalar controlled induction motor
drives. The experimental results of the implementations with their
analysis are detailed.
Abstract: This paper studies the pth moment exponential synchronization of a class of stochastic neural networks with mixed delays. Based on Lyapunov stability theory, by establishing a new integrodifferential inequality with mixed delays, several sufficient conditions have been derived to ensure the pth moment exponential stability for the error system. The criteria extend and improve some earlier results. One numerical example is presented to illustrate the validity of the main results.
Abstract: The knee bracing steel frame (KBF) is a new kind of energy dissipating frame, which combines excellent ductility and lateral stiffness. In this framing system, a special form of diagonal brace connected to a knee element instead of beam-column joint, is investigated. Recently, a similar system was proposed and named as chevron knee bracing system (CKB) which in comparison with the former system has a better energy absorption characteristic and at the same time retains the elastic nature of the structures. Knee bracing can provide a stiffer bracing system but reduces the ductility of the steel frame. Chevron knee bracing can be employed to provide the desired ductility level for a design. In this article, relation between seismic performance and structural parameters of the two above mentioned systems are investigated and compared. Frames with similar dimensions but various heights in both systems are designed according to Iranian code of practice for seismic resistant design of building, and then based on a non-linear push over static analysis; the seismic parameters such as behavior factor and performance levels are compared.
Abstract: Locality Sensitive Hashing (LSH) is one of the most
promising techniques for solving nearest neighbour search problem in
high dimensional space. Euclidean LSH is the most popular variation
of LSH that has been successfully applied in many multimedia
applications. However, the Euclidean LSH presents limitations that
affect structure and query performances. The main limitation of the
Euclidean LSH is the large memory consumption. In order to achieve
a good accuracy, a large number of hash tables is required. In this
paper, we propose a new hashing algorithm to overcome the storage
space problem and improve query time, while keeping a good
accuracy as similar to that achieved by the original Euclidean LSH.
The Experimental results on a real large-scale dataset show that the
proposed approach achieves good performances and consumes less
memory than the Euclidean LSH.
Abstract: Cellular automata have been used for design of cryptosystems. Recently some secret sharing schemes based on linear memory cellular automata have been introduced which are used for both text and image. In this paper, we illustrate that these secret sharing schemes are vulnerable to dishonest participants- collusion. We propose a cheating model for the secret sharing schemes based on linear memory cellular automata. For this purpose we present a novel uniform model for representation of all secret sharing schemes based on cellular automata. Participants can cheat by means of sending bogus shares or bogus transition rules. Cheaters can cooperate to corrupt a shared secret and compute a cheating value added to it. Honest participants are not aware of cheating and suppose the incorrect secret as the valid one. We prove that cheaters can recover valid secret by removing the cheating value form the corrupted secret. We provide methods of calculating the cheating value.
Abstract: Heavy metals have bad effects on environment and
soils and it can uptake by natural HAP .natural Hap is an inexpensive
material that uptake large amounts of various heavy metals like Zn
(II) .Natural HAP (N-HAP), extracted from bovine cortical bone ash,
is a good choice for substitution of commercial HAP. Several
experiments were done to investigate the sorption capacity of Zn (II)
to N-HAP in various particles sizes, temperatures, initial
concentrations, pH and reaction times. In this study, the sorption of
Zinc ions from a Zn solution onto HAP particles with sizes of 1537.6
nm and 47.6 nm at three initial pH values of 4.50, 6.00 and 7.50 was
studied. The results showed that better performance was obtained
through a 47.6 nm particle size and higher pH values. The
experimental data were analyzed using Langmuir, Freundlich, and
Arrhenius equations for equilibrium, kinetic and thermodynamic
studies. The analysis showed a maximum adsorption capacity of NHAP
as being 1.562 mmol/g at a pH of 7.5 and small particle size.
Kinetically, the prepared N-HAP is a feasible sorbent that retains Zn
(II) ions through a favorable and spontaneous sorption process.
Abstract: Composite laminates are relatively weak in out of
plane loading, inter-laminar stress, stress concentration near the edge
and stress singularities. This paper develops a new analytical
formulation for laminated composite rotating disc fabricated from
symmetric sequential quasi isotropic layers to predict three
dimensional stress and deformation. This analysis is necessary to
evaluate mechanical integrity of fiber reinforced multi-layer
laminates used for high speed rotating applications such as high
speed impellers. Three dimensional governing equations are written
for rotating composite disc. Explicit solution is obtained with
"Frobenius" expansion series. Based on analytical results, there are
two separate zones of three dimensional stress fields in centre and
edge of rotating disc. For thin discs, out of plane deformations and
stresses are small in comparison with plane ones. For relatively thick
discs deformation and stress fields are three dimensional.