Abstract: The reduction of energy consumption through improvements in energy efficiency has become an important goal for all industries, in order to improve the efficiency of the economy, and to reduce the emissions of Co2 caused by power generation. The objective of this paper is to investigate opportunities to increase process energy efficiency at the distillation unit of Shiraz oil refinery in south of Iran. The main aim of the project is to locate energy savings by use of pinch technology and to assess them. At first all the required data of hot and cold streams in preheating section of distillation unit has been extracted from the available flow sheets and then pinch analysis has been conducted. The present case study is a threshold one which does not need any utilities. After running range, targeting several heat exchanger networks were designed with respect to operating conditions and different ΔTmin. The optimal value of ΔTmin was calculated to be 22.3 °C. Based on this optimal value, there will be 5% reduction in annual total cost of heat exchanger network.
Abstract: In the present work, study of the vibration of thin cylindrical shells made of a functionally gradient material (FGM) composed of stainless steel and nickel is presented. Material properties are graded in the thickness direction of the shell according to volume fraction power law distribution. The objective is to study the natural frequencies, the influence of constituent volume fractions and the effects of boundary conditions on the natural frequencies of the FG cylindrical shell. The study is carried out using third order shear deformation shell theory. The governing equations of motion of FG cylindrical shells are derived based on shear deformation theory. Results are presented on the frequency characteristics, influence of constituent volume fractions and the effects of free-free boundary conditions.
Abstract: ZnO nanostructure were synthesized via microwave
method using zinc acetate as starting material, guanidinium as
structure directing agents, and water as solvent.. This work
investigates the photodegradation of azo dyes using the ZnO Flowerlike
in aqueous solutions. As synthesized ZnO samples were
characterized using X-Ray powder diffraction (XRD), scanning
electron microscopy (SEM), and FTIR spectroscopy.In this work
photodecolorization of congored azo dye under UV irradiation by
nano ZnO was studied.
Abstract: In this paper sensitivity analysis is performed for
reliability evaluation of power systems. When examining the
reliability of a system, it is useful to recognize how results
change as component parameters are varied. This knowledge
helps engineers to understand the impact of poor data, and
gives insight on how reliability can be improved. For these
reasons, a sensitivity analysis can be performed. Finally, a real
network was used for testing the presented method.
Abstract: Sedimentation process resulting from soil erosion in
the water basin especially in arid and semi-arid where poor
vegetation cover in the slope of the mountains upstream could
contribute to sediment formation. The consequence of sedimentation
not only makes considerable change in the morphology of the river
and the hydraulic characteristics but would also have a major
challenge for the operation and maintenance of the canal network
which depend on water flow to meet the stakeholder-s requirements.
For this reason mathematical modeling can be used to simulate the
effective factors on scouring, sediment transport and their settling
along the waterways. This is particularly important behind the
reservoirs which enable the operators to estimate the useful life of
these hydraulic structures. The aim of this paper is to simulate the
sedimentation and erosion in the eastern and western water intake
structures of the Dez Diversion weir using GSTARS-3 software. This
is done to estimate the sedimentation and investigate the ways in
which to optimize the process and minimize the operational
problems. Results indicated that the at the furthest point upstream of
the diversion weir, the coarser sediment grains tended to settle. The
reason for this is the construction of the phantom bridge and the
outstanding rocks just upstream of the structure. The construction of
these along the river course has reduced the momentum energy
require to push the sediment loads and make it possible for them to
settle wherever the river regime allows it. Results further indicated a
trend for the sediment size in such a way that as the focus of study
shifts downstream the size of grains get smaller and vice versa. It
was also found that the finding of the GSTARS-3 had a close
proximity with the sets of the observed data. This suggests that the
software is a powerful analytical tool which can be applied in the
river engineering project with a minimum of costs and relatively
accurate results.
Abstract: Bumpers play an important role in preventing the
impact energy from being transferred to the automobile and
passengers. Saving the impact energy in the bumper to be released in
the environment reduces the damages of the automobile and
passengers.
The goal of this paper is to design a bumper with minimum weight
by employing the Glass Material Thermoplastic (GMT) materials.
This bumper either absorbs the impact energy with its deformation or
transfers it perpendicular to the impact direction.
To reach this aim, a mechanism is designed to convert about 80%
of the kinetic impact energy to the spring potential energy and
release it to the environment in the low impact velocity according to
American standard1. In addition, since the residual kinetic energy
will be damped with the infinitesimal elastic deformation of the
bumper elements, the passengers will not sense any impact. It should
be noted that in this paper, modeling, solving and result-s analysis
are done in CATIA, LS-DYNA and ANSYS V8.0 software
respectively.
Abstract: In this study, ZnO nano rods and ZnO ultrafine particles were synthesized by Gel-casting method. The synthesized ZnO powder has a hexagonal zincite structure. The ZnO aggregates with rod-like morphology are typically 1.4 μm in length and 120 nm in diameter, which consist of many small nanocrystals with diameters of 10 nm. Longer wires connected by many hexahedral ZnO nanocrystals were obtained after calcinations at the temperature over 600° C.The crystalline structures and morphologies of the powder have been characterized by X-ray diffraction(XRD) and Scaning electron microscopy (SEM).The result shows that the different preparation conditions such as concentration H2O, calcinations time and calcinations temperature have a lot of influences upon the properties of nano ZnO powders, an increase in the temperature of the calcinations results in an increase of the grain size and also the increase of the calcinations time in high temperature makes the size of the grains bigger. The existences of extra watter prevent nano grains from improving like rod morphology. We have obtained the smallest grain size of ZnO powder by controlling the process conditions. Finally In a suitable condition, a novel nanostructure, namely bi-rod-like ZnO nano rods was found which is different from known ZnO nanostructures.
Abstract: In industrial scale of Gas to Liquid (GTL) process in
Fischer-Tropsch (FT) synthesis, a part of reactor outlet gases such as
CO2 and CH4 as side reaction products, is usually recycled. In this
study, the influence of CO2 and CH4 on the performance and
selectivity of Co-Ru/Al2O3 catalyst is investigated by injection of
these gases (0-20 vol. % of feed) to the feed stream. The effect of
temperature and feed flow rate, are also inspected. The results show
that low amounts of CO2 in the feed stream, doesn`t change the
catalyst activity significantly but increasing the amount of CO2 (more
than 10 vol. %) cause the CO conversion to decrease and the
selectivity of heavy components to increase. Methane acts as an inert
gas and doesn`t affect the catalyst performance. Increasing feed flow
rate has negative effect on both CO conversion and heavy component
selectivity. By raising the temperature, CO conversion will increase
but there are more volatile components in the product. The effect of
CO2 on the catalyst deactivation is also investigated carefully and a
mechanism is suggested to explain the negative influence of CO2 on
catalyst deactivation.
Abstract: The aim of this study was to investigate the influence
of reaction temperature and wheat straw moisture content on the
pyrolysis product yields, in the temperature range of 475-575 °C.
Samples of straw with moisture contents from 1.5 wt % to 15.0 wt %
were fed to a bench scale Pyrolysis Centrifuge Reactor (PCR). The
experimental results show that the changes in straw moisture content
have no significant effect on the distribution of pyrolysis product
yields. The maximum bio-oil yields approximately 60 (wt %, on dry
ash free feedstock basis) was observed around 525 °C - 550 °C for all
straw moisture levels. The water content in the wet straw bio-oil was
the highest. The heating value of bio-oil and solid char were
measured and the percentages of its energy distribution were
calculated. The energy distributions of bio-oil, char and gas were 56-
69 % 24-33 %, and 2-19 %, respectively.
Abstract: In this paper, a new approach is introduced to solve
Blasius equation using parameter identification of a nonlinear
function which is used as approximation function. Bees Algorithm
(BA) is applied in order to find the adjustable parameters of
approximation function regarding minimizing a fitness function
including these parameters (i.e. adjustable parameters). These
parameters are determined how the approximation function has to
satisfy the boundary conditions. In order to demonstrate the
presented method, the obtained results are compared with another
numerical method. Present method can be easily extended to solve a
wide range of problems.
Abstract: The one of most important objects in implementation
of damage analysis observations is manner of dam break wave
propagation. In this paper velocity and wave height due dam break in
with and without tailwater states for appointment hazardous lands
and flood radius are investigate. In order to modeling above
phenomenon finite volume method of Roe type for solving shallow
water equations is used. Results indicated that in the dry bed state
risk radius due to dam break is too high. While in the wet bed risk
radius has a less wide. Therefore in the first state constructions and
storage facilities are encountered with destruction risk. Further
velocity due to dam break in the second state is more comparing to
the first state. Hence erosion and scour the river bed in the dry bed is
too more compare to the wet bed.
Abstract: To produce sugar and ethanol, sugarcane processing
generates several agricultural residues, being straw and bagasse is
considered as the main among them. And what to do with this
residues has been subject of many studies and experiences in an
industry that, in recent years, highlighted by the ability to transform
waste into valuable products such as electric power. Cellulose is the
main component of these materials. It is the most common organic
polymer and represents about 1.5 x 1012 tons of total production of
biomass per year and is considered an almost inexhaustible source of
raw material. Pretreatment with mineral acids is one of the most
widely used as stage of cellulose extraction from lignocellulosic
materials for solubilizing most of the hemicellulose content. This
study had as goal to find the best reaction time of sugarcane bagasse
pretreatment with sulfuric acid in order to minimize the losses of
cellulose concomitantly with the highest possible removal of
hemicellulose and lignin. It was found that the best time for this
reaction was 40 minutes, in which it was reached a loss of
hemicelluloses around 70% and lignin and cellulose, around 15%.
Over this time, it was verified that the cellulose loss increased and
there was no loss of lignin and hemicellulose.
Abstract: In this paper, we define distance partition of vertex set of a graph G with reference to a vertex in it and with the help of the same, a graph with metric dimension two (i.e. β (G) = 2 ) is characterized. In the process, we develop a polynomial time algorithm that verifies if the metric dimension of a given graph G is two. The same algorithm explores all metric bases of graph G whenever β (G) = 2 . We also find a bound for cardinality of any distance partite set with reference to a given vertex, when ever β (G) = 2 . Also, in a graph G with β (G) = 2 , a bound for cardinality of any distance partite set as well as a bound for number of vertices in any sub graph H of G is obtained in terms of diam H .
Abstract: In the present article, nonlinear vibration analysis of
single layer graphene sheets is presented and the effect of small
length scale is investigated. Using the Hamilton's principle, the three
coupled nonlinear equations of motion are obtained based on the von
Karman geometrical model and Eringen theory of nonlocal
continuum. The solutions of Free nonlinear vibration, based on a one
term mode shape, are found for both simply supported and clamped
graphene sheets. A complete analysis of graphene sheets with
movable as well as immovable in-plane conditions is also carried out.
The results obtained herein are compared with those available in the
literature for classical isotropic rectangular plates and excellent
agreement is seen. Also, the nonlinear effects are presented as
functions of geometric properties and small scale parameter.
Abstract: This paper presents an approach for early breast
cancer diagnostic by employing combination of artificial neural
networks (ANN) and multiwaveletpacket based subband image
decomposition. The microcalcifications correspond to high-frequency
components of the image spectrum, detection of microcalcifications
is achieved by decomposing the mammograms into different
frequency subbands,, reconstructing the mammograms from the
subbands containing only high frequencies. For this approach we
employed different types of multiwaveletpacket. We used the result
as an input of neural network for classification. The proposed
methodology is tested using the Nijmegen and the Mammographic
Image Analysis Society (MIAS) mammographic databases and
images collected from local hospitals. Results are presented as the
receiver operating characteristic (ROC) performance and are
quantified by the area under the ROC curve.
Abstract: In the past few years, the use of wireless sensor networks (WSNs) potentially increased in applications such as intrusion detection, forest fire detection, disaster management and battle field. Sensor nodes are generally battery operated low cost devices. The key challenge in the design and operation of WSNs is to prolong the network life time by reducing the energy consumption among sensor nodes. Node clustering is one of the most promising techniques for energy conservation. This paper presents a novel clustering algorithm which maximizes the network lifetime by reducing the number of communication among sensor nodes. This approach also includes new distributed cluster formation technique that enables self-organization of large number of nodes, algorithm for maintaining constant number of clusters by prior selection of cluster head and rotating the role of cluster head to evenly distribute the energy load among all sensor nodes.
Abstract: Speeded-Up Robust Feature (SURF) is commonly used for feature matching in stereovision because of their robustness towards scale changes and rotational changes. However, SURF feature cannot cope with large viewpoint changes or skew distortion. This paper introduces a method which can help to improve the wide baseline-s matching performance in term of accuracy by rectifying the image using two vanishing points. Simplified orientation correction was used to remove the false matching..
Abstract: The present work was conducted for the synthesis of
nano size zerovalent iron (nZVI) and hexavalent chromium (Cr(VI))
removal as a highly toxic pollutant by using this nanoparticles. Batch
experiments were performed to investigate the effects of Cr(VI),
nZVI concentration, pH of solution and contact time variation on
the removal efficiency of Cr(VI). nZVI was synthesized by
reduction of ferric chloride using sodium borohydrid. SEM and
XRD examinations applied for determination of particle size and
characterization of produced nanoparticles. The results showed that
the removal efficiency decreased with Cr(VI) concentration and pH
of solution and increased with adsorbent dosage and contact time.
The Langmuir and Freundlich isotherm models were used for the
adsorption equilibrium data and the Langmuir isotherm model was
well fitted. Nanoparticle ZVI presented an outstanding ability to
remove Cr(VI) due to high surface area, low particle size and high
inherent activity.
Abstract: TiO2 nanoparticles were synthesized by hydrothermal
method at 180°C from TiOSO4 aqueous solution with1m/l
concentration. The obtained products were coated with silica by
means of a seeded polymerization technique for a coating time of
1440 minutes to obtain well defined TiO2@SiO2 core-shell structure.
The uncoated and coated nanoparticles were characterized by using
X-Ray diffraction technique (XRD), Fourier Transform Infrared
Spectroscopy (FT-IR) to study their physico-chemical properties.
Evidence from XRD and FTIR results show that SiO2 is
homogenously coated on the surface of titania particles. FTIR spectra
show that there exists an interaction between TiO2 and SiO2 and
results in the formation of Ti-O-Si chemical bonds at the interface of
TiO2 particles and SiO2 coating layer. The non linear optical limiting
properties of TiO2 and TiO2@SiO2 nanoparticles dispersed in
ethylene glycol were studied at 532nm using 5ns Nd:YAG laser
pulses. Three-photon absorption is responsible for optical limiting
characteristics in these nanoparticles and it is seen that the optical
nonlinearity is enhanced in core-shell structures when compared with
single counterparts. This effective three-photon type absorption at
this wavelength, is of potential application in fabricating optical
limiting devices.
Abstract: This article explores the self-identity of the Kazakh
people by way of identifying the roots of self-understanding in
Kazakh culture. Unfortunately, Western methods of ethno
psychology cannot fully capture what is unique about identity in
Kazakh culture. Although Kazakhstan is the ninth largest country in
terms of geographical space, Kazakh cultural identity is not wellknown
in the West. In this article we offer an account of the national
psychological features of the Kazakh people, in order to reveal the
spiritual, mental, ethical dimensions of modern Kazakhs. These
factors play a central role in the revival of forms of identity that are
central to the Kazakh people.