Abstract: In this study, the conversion of n-pentane to aromatics is investigated on HZSM-5 zeolites modified by Ga ion-exchange and silylation using tetraethyl orthosilicate (TEOS) via chemical liquid deposition (CLD). The effect of SiO2/Al2O3 ratios of HZSM-5 was also studied. Parameters in preparing catalysts i.e. TEOS loading and cycles of deposition were varied to obtain the optimal condition for enhancing p-xylene selectivity. The highest p-xylene selectivity 99.7% was achieved when the amount of TEOS was 20 vol.%.The catalysts were characterized by TPD, TPO, XRF, and BET. Results show that the conversion of n-pentane was influenced remarkably by the SiO2/Al2O3 ratios of HZSM-5. The highest p-xylene selectivity 99.7% was achieved when the amount of TEOS was 20 vol.%. And cycles of deposition greatly improves HZSM-5 shape-selectivity.
Abstract: Sol-gel method has been used to fabricate
nanocomposite films on glass substrates composed halloysite clay
mineral and nanocrystalline TiO2. The methodology for the synthesis
involves a simple chemistry method utilized nonionic surfactant
molecule as pore directing agent along with the acetic acid-based solgel
route with the absence of water molecules. The thermal treatment
of composite films at 450oC ensures elimination of organic material
and lead to the formation of TiO2 nanoparticles onto the surface of
the halloysite nanotubes. Microscopy techniques and porosimetry
methods used in order to delineate the structural characteristics of the
materials. The nanocomposite films produced have no cracks and
active anatase crystal phase with small crystallite size were deposited
on halloysite nanotubes. The photocatalytic properties for the new
materials were examined for the decomposition of the Basic Blue 41
azo dye in solution. These, nanotechnology based composite films
show high efficiency for dye’s discoloration in spite of different
halloysite quantities and small amount of halloysite/TiO2 catalyst
immobilized onto glass substrates. Moreover, we examined the
modification of the halloysite/TiO2 films with silver particles in order
to improve the photocatalytic properties of the films. Indeed, the
presence of silver nanoparticles enhances the discoloration rate of the
Basic Blue 41 compared to the efficiencies obtained for unmodified
films.
Abstract: The effect of Alumina nanoparticle size on thermophysical
properties, heat transfer performance and pressure loss characteristics of
Aviation Turbine Fuel (ATF)-Al2O3 nanofluids is studied experimentally for
the proposed application of regenerative cooling of semi-cryogenic rocket
engine thrust chambers. Al2O3 particles with mean diameters of 50 nm or 150
nm are dispersed in ATF. At 500C and 0.3% particle volume concentration,
the bigger particles show increases of 17% in thermal conductivity and 55% in
viscosity, whereas the smaller particles show corresponding increases of 21%
and 22% for thermal conductivity and viscosity respectively. Contrary to these
results, experiments to study the heat transfer performance and pressure loss
characteristics show that at the same pumping power, the maximum
enhancement in heat transfer coefficient at 500C and 0.3% concentration is
approximately 47% using bigger particles, whereas it is only 36% using
smaller particles.
Abstract: The notions of intuitionistic fuzzy h-ideal and normal
intuitionistic fuzzy h-ideal in Γ-hemiring are introduced and some
of the basic properties of these ideals are investigated. Cartesian
product of intuitionistic fuzzy h-ideals is also defined. Finally a
characterization of intuitionistic fuzzy h-ideals in terms of fuzzy
relations is obtained.
Abstract: This research were investigated, determined, and
analyzed of the climate characteristically change in the provincial
Udon Thani in the period of 60 surrounding years from 1951 to 2010
A.D. that it-s transferred to effects of climatologically data for
determining global warming. Statistically significant were not found
for the 60 years- data (R2
Abstract: The main issue in sweetening natural gas is H2S
dissociation. The present study is concerned with simulating thermal
dissociation of H2S in industrial natural gas carbon black furnace.
The comparison of calculated results against experimental
measurements shows good agreement. The results show that sulfur
derived from H2S thermal dissociation peaked at φ=0.95. H2S
thermal dissociation is enhanced in equivalence ratio upper than 1
and H2S oxidization is increased in equivalence ratio lower than 1.
H2 concentration of H2S thermal dissociation is increased with
increase of equivalence ratio up to 1. Also, H2S concentration
decreased in outlet as equivalence ratio increases. H2S thermal
dissociation to hydrogen and Sulfur reduces its toxic characteristics
and make economical benefits.
Abstract: This paper investigates the aerodynamic characters of a model ducted fan system, analyses the basic principle of the effect of thrust promotion and torque reduction, discovers the relationship between the revolutions per minute(RPM) of the fan and the characters of thrust, as well as system torque. Firstly a model ducted fan has been designed and manufactured according to the specific structure of flow field, then CFD simulation has been carried out to analyze such aerodynamics, finally bench tests have been used to validate the simulation results and system configuration.
Abstract: Ultrastructure of duodenum mucosa of irradiated rat
was studied versus dose rate of irradiation following exposure to
gamma rays from 60-Cobalt source. The animals were whole body
irradiated at two dose rates (1 Gy.mn-1 and 1 Gy.h-1) and three total
doses (1, 2 or 4 Gy) for each dose rate. 24 or 48 h after irradiation,
their small intestine was removed and samples of duodenum were
processed for observations under a transmission electron microscopy.
Samples of duodenum mucosa of control rats were processed in the
same way. For the lower dose rate of 1 Gy.h-1, main lesions
characteristic of apoptosis were detected within irradiated enterocytes
at a total dose of 2 Gy and 24 h after exposure. Necrosis was noted in
the samples, 48 h after exposition. For the higher dose rate of 1
Gy.mn-1, fewer changes were detected at all total doses 24 or 48 h
irradiation. Thus, it was shown that the appearance of radiationinduced
alterations varies not only with increasing total dose and
post-irradiation time but especially with decreasing dose rate.
Abstract: On-line handwritten scripts are usually dealt with pen tip traces from pen-down to pen-up positions. Time evaluation of the pen coordinates is also considered along with trajectory information. However, the data obtained needs a lot of preprocessing including filtering, smoothing, slant removing and size normalization before recognition process. Instead of doing such lengthy preprocessing, this paper presents a simple approach to extract the useful character information. This work evaluates the use of the counter- propagation neural network (CPN) and presents feature extraction mechanism in full detail to work with on-line handwriting recognition. The obtained recognition rates were 60% to 94% using the CPN for different sets of character samples. This paper also describes a performance study in which a recognition mechanism with multiple thresholds is evaluated for counter-propagation architecture. The results indicate that the application of multiple thresholds has significant effect on recognition mechanism. The method is applicable for off-line character recognition as well. The technique is tested for upper-case English alphabets for a number of different styles from different peoples.
Abstract: The paper reports the preparation and photocatalytic
activity of ZnO/SnO2 and SnO2 nanoparticles. These nanoparticles
were synthesized by hydrothermal method. The products were
characterized by X-ray diffraction (XRD) and scanning electron
microscopy (SEM). Their grain sizes are about 50-100 nm. The
photocatalytic activities of these materials were investigated for
congo red removal from aqueous solution under UV light irradiation.
It was shown that the use of ZnO/SnO2 as photocatalyst have better
photocatalytic activity for degradation of congo red than SnO2 or
TiO2 (anatase, particle size: 30nm) alone.
Abstract: Most real world systems express themselves formally
as a set of nonlinear algebraic equations. As applications grow, the
size and complexity of these equations also increase. In this work, we
highlight the key concepts in using the homotopy analysis method
as a methodology used to construct efficient iteration formulas for
nonlinear equations solving. The proposed method is experimentally
characterized according to a set of determined parameters which
affect the systems. The experimental results show the potential and
limitations of the new method and imply directions for future work.
Abstract: In this article, LQR based PID controller design for
3DOF helicopter system is investigated. The 3-DOF helicopter
system is a benchmark laboratory model having strongly nonlinear
characteristics and unstable dynamics which make the control of such
system a challenging task. This article first presents the mathematical
model of the 3DOF helicopter system and then illustrates the basic
idea and technical formulation for controller design. The paper
explains the simple approach for the approximation of PID design
parameters from the LQR controller gain matrix. The simulation
results show that the investigated controller has both static and
dynamic performance, therefore the stability and the quick control
effect can be obtained simultaneously for the 3DOF helicopter
system.
Abstract: A lot of recent research have spoken on the relation
between the increase of the homocysteinemia and some kinds of
cancer . For that, our study was based on the research of a possible
relation between the increase of the concentration of this amino-acid
in the plasma and the appearance of the disease of the Acute
Lymphoblastic Leukaemia in a part of Algerian children with Berber
origin in the East of Algeria . The study has done on 47 ill persons
with an average age of (09±06 ) years , with whom the disease has
diagnosed by blood and marrow examination in the hospital of blood
diseases in the CHU of Batna, and on 194 healthy witnesses of the
same age. The two groups were benefited by a dosage of the
concentration of the homocysteine vitamin B9 ,vitamin B12 , and
also of the study of special polymorphisms of indispensable enzymes
in the metabolism of this acid , and that by the use of the method (
Light cycler ) Real time PCR , on the following enzymes : MS (
C2756G ), MSR ( A66G ) ,MTHFR1 ( C677T ) and MTHFR2
(A1298C). The obtained results have revealed that the rate of the
homozygote muted genotype is the less frequent in the two groups ,
and that exist at list one genotype of each enzyme in the ill group and
in which the percentage exceed with remarkable way the same
genotype in the healthy group and we notice specially the muted
genotype GG of -the methionine synthetase-and the form TT of the
enzyme – methyline tetra hydrofolate reductase – We notice the
existence of considerable number of genotypes in the ill group lied
with characteristic increase of this Amino-acid ,and that for the
reduction of the biologic activity of these enzymes which become
inefficient in the transfer of the homocysteine into the methionine
and cause the diminution of the biologic activity of these enzymes
and with consequence the reduction of the percentage of methylic
radicals in the DNA of studied genes and that lead to the increase of
the activity and the capacity of transcription , and it-s so probably
that this last one is one of the factors of this disease especially if we
know that the specific check-up of vitamins is normal and similar in
the two groups , which ovoid the hypothesis of the reduction of
vitamins . We notice also that the heterozygote genotype is the less in
the sick category except the MTHFR2. Wild genotype is more
frequent in the witness group except MSR. Even these results are
partials; they open a new way in the genetic diagnosis of this
malicious disease which allow a precocious diagnosis and the use of
an effective and appropriated treatment in the same time.
Abstract: A macroscopic constitutive equation is developed for a high-density cellulose insulation material with emphasis on the outof- plane stress relaxation behavior. A hypothesis is proposed where the total stress is additively composed by an out-of-plane visco-elastic isotropic contribution and an in-plane elastic orthotropic response. The theory is validated against out-of-plane stress relaxation, compressive experiments and in-plane tensile hysteresis, respectively. For large scale finite element simulations, the presented model provides a balance between simplicity and capturing the materials constitutive behaviour.
Abstract: A design flow of multi-standard down-conversion
CMOS mixers for three modern standards: Global System Mobile,
Digital Enhanced Cordless Telephone and Universal Mobile
Telecommunication Systems is presented. Three active mixer-s
structures are studied. The first is based on the Gilbert cell which
gives a tolerable noise figure and linearity with a low conversion
gain. The second and third structures use the current bleeding and
charge injection techniques in order to increase the conversion gain.
An improvement of about 2 dB of the conversion gain is achieved
without a considerable degradation of the other characteristics. The
models used for noise figure, conversion gain and IIP3 used are
studied. This study describes the nature of trade-offs inherent in such
structures and gives insights that help in identifying which structure
is better for given conditions.
Abstract: Polymeric microreactors have emerged as a new
generation of carriers that hold tremendous promise in the areas of
cancer therapy, controlled delivery of drugs, for removal of
pollutants etc. Present work reports a simple and convenient
methodology for synthesis of polystyrene and poly caprolactone
microreactors. An aqueous suspension of carboxylated (1μm)
polystyrene latex particles was mixed with toluene solution followed
by freezing with liquid nitrogen. Freezed particles were incubated at
-20°C and characterized for formation of voids on the surface of
polymer microspheres by Field Emission Scanning Electron
Microscope. The hollow particles were then overnight incubated at
40ºC with unfunctionalized quantum dots (QDs) in 5:1 ratio. QDs
Encapsulated polystyrene microcapsules were characterized by
fluorescence microscopy.
Likewise Poly ε-caprolactone microreactors were prepared by
micro-volcanic rupture of freeze dried microspheres synthesized
using emulsification of polymer with aqueous Poly vinyl alcohol and
freezed with liquid nitrogen. Microreactors were examined with Field
Emission Scanning Electron Microscope for size and morphology.
Current study is an attempt to create hollow polymer particles which
can be employed for microencapsulation of nanoparticles and drug
molecules.
Abstract: A Finite Volume method based on Characteristic Fluxes for compressible fluids is developed. An explicit cell-centered resolution is adopted, where second and third order accuracy is provided by using two different MUSCL schemes with Minmod, Sweby or Superbee limiters for the hyperbolic part. Few different times integrator is used and be describe in this paper. Resolution is performed on a generic unstructured Cartesian grid, where solid boundaries are handled by a Cut-Cell method. Interfaces are explicitely advected in a non-diffusive way, ensuring local mass conservation. An improved cell cutting has been developed to handle boundaries of arbitrary geometrical complexity. Instead of using a polygon clipping algorithm, we use the Voxel traversal algorithm coupled with a local floodfill scanline to intersect 2D or 3D boundary surface meshes with the fixed Cartesian grid. Small cells stability problem near the boundaries is solved using a fully conservative merging method. Inflow and outflow conditions are also implemented in the model. The solver is validated on 2D academic test cases, such as the flow past a cylinder. The latter test cases are performed both in the frame of the body and in a fixed frame where the body is moving across the mesh. Adaptive Cartesian grid is provided by Paramesh without complex geometries for the moment.
Abstract: In textile industry, besides the conventional textile
products, technical textile goods, that have been brought external
functional properties into, are being developed for technical textile
industry. Especially these products produced with weaving
technology are widely preferred in areas such as sports, geology,
medical, automotive, construction and marine sectors. These textile
products are exposed to various stresses and large deformations under
typical conditions of use. At this point, sufficient and reliable data
could not be obtained with uniaxial tensile tests for determination of
the mechanical properties of such products due to mainly biaxial
stress state. Therefore, the most preferred method is a biaxial tensile
test method and analysis. These tests and analysis is applied to fabrics
with different functional features in order to establish the textile
material with several characteristics and mechanical properties of the
product. Planar biaxial tensile test, cylindrical inflation and bulge
tests are generally required to apply for textile products that are used
in automotive, sailing and sports areas and construction industry to
minimize accidents as long as their service life. Airbags, seat belts
and car tires in the automotive sector are also subject to the same
biaxial stress states, and can be characterized by same types of
experiments. In this study, in accordance with the research literature
related to the various biaxial test methods are compared. Results with
discussions are elaborated mainly focusing on the design of a biaxial
test apparatus to obtain applicable experimental data for developing a
finite element model. Sample experimental results on a prototype
system are expressed.
Abstract: Horizontal continuous casting is widely used to
produce semi-finished non-Ferrous products. Homogeneity in the
metallurgical characteristics and mechanical properties for this
product is vital for industrial application. In the present work, the
microstructure and mechanical properties of a horizontal continuous
cast two-phase brass billet have been studied. Impact strength and
hardness variations were examined and the phase composition and
porosity studied with image analysis software. Distinct differences in
mechanical properties were observed between the upper, middle and
lower parts of the billet, which are explained in terms of the
morphology and size of the phase in the microstructure. Hardness
variation in the length of billet is higher in upper area but impact
strength is higher in lower areas.
Abstract: The paper presents the results of a series of
experiments conducted on physical models of Quarter-circle
breakwater (QBW) in a two dimensional monochromatic wave
flume. The purpose of the experiments was to evaluate the reflection
coefficient Kr of QBW models of different radii (R) for different
submergence ratios (d/hc), where d is the depth of water and hc is the
height of the breakwater crest from the sea bed. The radii of the
breakwater models studied were 20cm, 22.5cm, 25cm, 27.5cm and
submergence ratios used varied from 1.067 to 1.667. The wave
climate off the Mangalore coast was used for arriving at the various
model wave parameters. The incident wave heights (Hi) used in the
flume varied from 3 to 18cm, and wave periods (T) ranged from 1.2 s
to 2.2 s. The water depths (d) of 40cm, 45cm and 50cm were used in
the experiments. The data collected was analyzed to compute
variation of reflection coefficient Kr=Hr/Hi (where Hr=reflected wave
height) with the wave steepness Hi/gT2 for various R/Hi
(R=breakwater radius) values. It was found that the reflection
coefficient increased as incident wave steepness increased. Also as
wave height decreases reflection coefficient decreases and as
structure radius R increased Kr decreased slightly.