Abstract: In this present study, experimental work was
conducted to study the effectiveness of newly innovated steel-CFRP
composite (CFRP laminates sandwiched between two steel strips) as
stirrups. A total numbers of eight concrete beams were tested under
four point loads. Each beam measured 1600 mm long, 160mm width
and 240 mm depth. The beams were reinforced with different shear
reinforcements; one without stirrups, one with steel stirrups and six
with different types and numbers of steel-CRFR stirrups. Test results
indicated that the steel-CFRP stirrups had enhanced the shear
strength capacity of beams. Moreover, the tests revealed that steel-
CFRP stirrups reached to their ultimate tensile strength unlike FRP
stirrups which rupture at much lower level than their ultimate
strength as werereported in various researches.
Abstract: This paper proposes a three-phase four-wire currentcontrolled
Voltage Source Inverter (CC-VSI) for both power quality
improvement and PV energy extraction. For power quality
improvement, the CC-VSI works as a grid current-controlling shunt
active power filter to compensate for harmonic and reactive power of
loads. Then, the PV array is coupled to the DC bus of the CC-VSI
and supplies active power to the grid. The MPPT controller employs
the particle swarm optimization technique. The output of the MPPT
controller is a DC voltage that determines the DC-bus voltage
according to PV maximum power. The PSO method is simple and
effective especially for a partially shaded PV array. From computer
simulation results, it proves that grid currents are sinusoidal and inphase
with grid voltages, while the PV maximum active power is
delivered to loads.
Abstract: Recently, there have been an increasing interest in RFID system and RFID systems have been applied to various applications. Load balancing is a fundamental technique for providing scalability of systems by moving workload from overloaded nodes to under-loaded nodes. This paper presents an approach to adaptive load balancing for RFID middlewares. Workloads of RFID middlewares can have a considerable variation according to the location of the connected RFID readers and can abruptly change at a particular instance. The proposed approach considers those characteristics of RFID middle- wares to provide an efficient load balancing.
Abstract: Video sensor networks operate on stringent requirements
of latency. Packets have a deadline within which they have
to be delivered. Violation of the deadline causes a packet to be
treated as lost and the loss of packets ultimately affects the quality
of the application. Network latency is typically a function of many
interacting components. In this paper, we propose ways of reducing
the forwarding latency of a packet at intermediate nodes. The
forwarding latency is caused by a combination of processing delay
and queueing delay. The former is incurred in order to determine the
next hop in dynamic routing. We show that unless link failures in a
very specific and unlikely pattern, a vast majority of these lookups
are redundant. To counter this we propose source routing as the
routing strategy. However, source routing suffers from issues related
to scalability and being impervious to network dynamics. We propose
solutions to counter these and show that source routing is definitely
a viable option in practical sized video networks. We also propose a
fast and fair packet scheduling algorithm that reduces queueing delay
at the nodes. We support our claims through extensive simulation on
realistic topologies with practical traffic loads and failure patterns.
Abstract: Thermal water hammer is a special type of water
hammer which rarely occurs in heat exchangers. In biphasic fluids, if
steam bubbles are surrounded by condensate, regarding lower
condensate temperature than steam, they will suddenly collapse. As a
result, the vacuum caused by an extreme change in volume lead to
movement of the condensates in all directions and their collision the
force produced by this collision leads to a severe stress in the pipe
wall. This phenomenon is a special type of water hammer. According
to fluid mechanics, this phenomenon is a particular type of transient
flows during which abrupt change of fluid leads to sudden pressure
change inside the tube. In this paper, the mechanism of abrupt failure
of 80 tubes of 481 tubes of a methanol heat exchanger is discussed.
Initially, due to excessive temperature differences between heat
transfer fluids and simultaneous failure of 80 tubes, thermal shock
was presupposed as the reason of failure. Deeper investigation on
cross-section of failed tubes showed that failure was, ductile type of
failure, so the first hypothesis was rejected. Further analysis and more
accurate experiments revealed that failure of tubes caused by thermal
water hammer. Finally, the causes of thermal water hammer and
various solutions to avoid such mechanism are discussed.
Abstract: Artificial Intelligence (AI) methods are increasingly being used for problem solving. This paper concerns using AI-type learning machines for power quality problem, which is a problem of general interest to power system to provide quality power to all appliances. Electrical power of good quality is essential for proper operation of electronic equipments such as computers and PLCs. Malfunction of such equipment may lead to loss of production or disruption of critical services resulting in huge financial and other losses. It is therefore necessary that critical loads be supplied with electricity of acceptable quality. Recognition of the presence of any disturbance and classifying any existing disturbance into a particular type is the first step in combating the problem. In this work two classes of AI methods for Power quality data mining are studied: Artificial Neural Networks (ANNs) and Support Vector Machines (SVMs). We show that SVMs are superior to ANNs in two critical respects: SVMs train and run an order of magnitude faster; and SVMs give higher classification accuracy.
Abstract: The basis of this paper is the assumption, that graviton
is a measurable entity of molecular gravitational acceleration and this
is not a hypothetical entity. The adoption of this assumption as an
axiom is tantamount to fully opening the previously locked door to
the boundary theory between laminar and turbulent flows. It leads to
the theorem, that the division of flows of Newtonian (viscous) fluids
into laminar and turbulent is true only, if the fluid is influenced by a
powerful, external force field. The mathematical interpretation of this
theorem, presented in this paper shows, that the boundary between
laminar and turbulent flow can be determined theoretically. This is a
novelty, because thus far the said boundary was determined
empirically only and the reasons for its existence were unknown.
Abstract: Due to the high increase in and demand for a wide assortment of applications that require low-cost, high-efficiency, and compact systems, RF power amplifiers are considered the most critical design blocks and power consuming components in wireless communication, TV transmission, radar, and RF heating. Therefore, much research has been carried out in order to improve the performance of power amplifiers. Classes-A, B, C, D, E and F are the main techniques for realizing power amplifiers.
An implementation of high efficiency class-F power amplifier with Gallium Nitride (GaN) High Electron Mobility Transistor (HEMT) was realized in this paper. The simulation and optimization of the class-F power amplifier circuit model was undertaken using Agilent’s Advanced Design system (ADS). The circuit was designed using lumped elements.
Abstract: Composite of Celatom-ZeoliteY (Cel-ZY) was used to
remove cobalt ion from an aqueous solution using batch mode.
ZeoliteY has successfully superimposed on Celatom FW-14 surface
using hydrothermal treatment .The product was synthesized as a
novel of hierarchical porous material. It was observed from the
results that Cel-ZY has higher ability to remove cobalt ions than the
pure ZeoliteY powder (PZY) synthesized under the same conditions.
Several parameters were studied in this project to investigate the
effect of removal cobalt ion such as pH and initial cobalt
concentration. It was clearly observed that the uptake of cobalt ions
was affected with increase these parameters. The results proved that
the product can be used effectively to remove Co2+ ions from
wastewater as an environmentally friendly alternative.
Abstract: In this study, the sorption of Malachite green (MG) on Hydrilla verticillata biomass, a submerged aquatic plant, was investigated in a batch system. The effects of operating parameters such as temperature, adsorbent dosage, contact time, adsorbent size, and agitation speed on the sorption of Malachite green were analyzed using response surface methodology (RSM). The proposed quadratic model for central composite design (CCD) fitted very well to the experimental data that it could be used to navigate the design space according to ANOVA results. The optimum sorption conditions were determined as temperature - 43.5oC, adsorbent dosage - 0.26g, contact time - 200min, adsorbent size - 0.205mm (65mesh), and agitation speed - 230rpm. The Langmuir and Freundlich isotherm models were applied to the equilibrium data. The maximum monolayer coverage capacity of Hydrilla verticillata biomass for MG was found to be 91.97 mg/g at an initial pH 8.0 indicating that the optimum sorption initial pH. The external and intra particle diffusion models were also applied to sorption data of Hydrilla verticillata biomass with MG, and it was found that both the external diffusion as well as intra particle diffusion contributes to the actual sorption process. The pseudo-second order kinetic model described the MG sorption process with a good fitting.
Abstract: The aim of this study was to synthesize the single
walled carbon nanotubes (SWCNTs) and determine their hydrogen
storage capacities. SWCNTs were firstly synthesized by chemical
vapor deposition (CVD) of acetylene (C2H2) on a magnesium oxide
(MgO) powder impregnated with an iron nitrate (Fe(NO3)3·9H2O)
solution. The synthesis parameters were selected as: the synthesis
temperature of 800°C, the iron content in the precursor of 5% and the
synthesis time of 30 min. Purification process of SWCNTs was
fulfilled by microwave digestion at three different temperatures (120,
150 and 200 °C), three different acid concentrations (0.5, 1 and 1.5
M) and for three different time intervals (15, 30 and 60 min). Nitric
acid (HNO3) was used in the removal of the metal catalysts. The
hydrogen storage capacities of the purified materials were measured
using volumetric method at the liquid nitrogen temperature and gas
pressure up to 100 bar. The effects of the purification conditions such
as temperature, time and acid concentration on hydrogen adsorption
were investigated.
Abstract: Calcium is a vital second messenger used in signal transduction. Calcium controls secretion, cell movement, muscular contraction, cell differentiation, ciliary beating and so on. Two theories have been used to simplify the system of reaction-diffusion equations of calcium into a single equation. One is excess buffer approximation (EBA) which assumes that mobile buffer is present in excess and cannot be saturated. The other is rapid buffer approximation (RBA), which assumes that calcium binding to buffer is rapid compared to calcium diffusion rate. In the present work, attempt has been made to develop a model for calcium diffusion under excess buffer approximation in neuron cells. This model incorporates the effect of [Na+] influx on [Ca2+] diffusion,variable calcium and sodium sources, sodium-calcium exchange protein, Sarcolemmal Calcium ATPase pump, sodium and calcium channels. The proposed mathematical model leads to a system of partial differential equations which have been solved numerically using Forward Time Centered Space (FTCS) approach. The numerical results have been used to study the relationships among different types of parameters such as buffer concentration, association rate, calcium permeability.
Abstract: Despite the relatively large number of studies that
have examined the use of appeals in advertisements, research on the
use of appeals in green advertisements is still underdeveloped and
needs to be investigated further, as it is definitely a tool for marketers
to create illustrious ads. In this study, content analysis was employed
to examine the nature of green advertising appeals and to match the
appeals with the green advertisements. Two different types of green
print advertisings, product orientation and organizational image
orientation were used. Thirty highly educated participants with
different backgrounds were asked individually to ascertain three
appeals out of thirty-four given appeals found among forty real green
advertisements. To analyze participant responses and to group them
based on common appeals, two-step K-mean clustering is used. The
clustering solution indicates that eye-catching graphics and
imaginative appeals are highly notable in both types of green ads.
Depressed, meaningful and sad appeals are found to be highly used in
organizational image orientation ads, whereas, corporate image,
informative and natural appeals are found to be essential for product
orientation ads.
Abstract: In recent years, several severe large-scale influenza
outbreaks happened in many countries, such as SARS in 2005 or
H1N1 in 2009. Those influenza Epidemics have greatly impacts not
only on people-s life and health, but medical systems in different
countries. Although severe diseases are more experienced, they are not
fully controlled. Governments have different policies to control the
spreads of diseases. However, those policies have both positive and
negative social or economical influence on people and society.
Therefore, it is necessary and essential to develop an appropriate
model for evaluations of policies. Consequently, a proper measure can
be implemented to confront the diseases. The main goal of this study is
to develop a SIR-based model for the further evaluations of the
candidate policies during the influenza outbreaks.
Abstract: Nowadays, one of the most important problems of the
metropolises and the world large cities is the habitant traffic difficulty
and lack of sufficient parking site for the vehicles. Esfahan city as the
third metropolis of Iran has encountered with the vehicles parkingplace
problems in the most parts of fourteen regions of the city. The
non principled and non systematic dispersal and lack of parking sites
in the city has created an unfavorable status for its traffic and has
caused the air and sound pollutions increase; in addition, it wastes the
most portions of the citizenship and travelers' charge and time in
urban pathways and disturbs their mental and psychical calmness,
thus leads to their intensive dissatisfaction. In this study, by the usage
of AHP model in GIS environment, the effective criteria in selecting
the public parking sites have been combined with each other, and the
results of the created layers overlapping represent the parking
utilitarian vastness and widths. The achieved results of this research
indicate the pretty appropriate public parking sites selection in region
number 3 of Esfahan; but inconsequential dispersal and lack of these
parking sites in this region have caused abundant transportation
problems in Esfahan city.
Abstract: This paper presents a new general technique for analysis of noise in static log-domain translinear circuits. It is demonstrated that employing this technique, leads to a general, simple and routine method of the noise analysis. The circuit has been simulated by HSPICE. The simulation results are seen to conform to the theoretical analysis and shows benefits of the proposed circuit.
Abstract: Analytical investigation of the sedimentation
processes in the river engineering and hydraulic structures is of vital
importance as this can affect water supply for the cultivating lands in
the command area. The reason being that gradual sediment formation
behind the reservoir can reduce the nominal capacity of these dams.
The aim of the present paper is to analytically investigate
sedimentation process along the river course and behind the storage
reservoirs in general and the Eastern Intake of the Dez Diversion weir
in particular using the SHARC software. Results of the model
indicated the water level at 115.97m whereas the real time
measurement from the river cross section was 115.98 m which
suggests a significantly close relation between them. The average
transported sediment load in the river was measured at 0.25mm ,
from which it can be concluded that nearly 100% of the suspended
loads in river are moving which suggests no sediment settling but
indicates that almost all sediment loads enters into the intake. It was
further showed the average sediment diameter entering the intake to
be 0.293 mm which in turn suggests that about 85% of suspended
sediments in the river entre the intake. Comparison of the results
from the SHARC model with those obtained form the SSIIM
software suggests quite similar outputs but distinguishing the
SHARC model as more appropriate for the analysis of simpler
problems than other model.
Abstract: In this paper, a new Genetic Algorithm (GA) based
methodology is proposed to optimize the Degree of Hybridization
(DOH) in a passenger parallel hybrid car. At first step, target
parameters for the vehicle are decided and then using ADvanced
VehIcle SimulatOR (ADVISOR) software, the variation pattern of
these target parameters, across the different DOHs, is extracted. At
the next step, a suitable cost function is defined and is optimized
using GA. In this paper, also a new technique has been proposed for
deciding the number of battery modules for each DOH, which leads
to a great improvement in the vehicle performance. The proposed
methodology is so simple, fast and at the same time, so efficient.
Abstract: The purpose of this research study is to investigate the manner in which various loads affect the mechanical properties of the formed mild steel plates. The investigation focuses on examining the cross-sectional area of the metal plate at the centre of the formed mild steel plate. Six mild steel plates were deformed with different loads. The loads applied on the plates had a magnitude of 5 kg, 10 kg, 15 kg, 20 kg, 25 kg and 30 kg. The radius of the punching die was 120 mm and the loads were applied at room temperature. The investigations established that the applied load causes the Vickers microhardness at the cross-sectional area of the plate to increase due to strain hardening. Hence, the percentage increase of the hardness due to the load was found to be directly proportional to the increase in the load. Furthermore, the tensile test results for the parent material showed that the average Ultimate Tensile Strength (UTS) for the three samples was 308 MPa while the average Yield Strength and Percentage Elongation were 227 MPa and 38 % respectively. Similarly, the UTS of the formed components increased after the deformation of the plate, as such it can be concluded that the forming loads alter the mechanical properties of the materials by improving and strengthening the material properties.
Abstract: In recent years, the underground water sources in
southern Taiwan have become salinized because of saltwater
intrusions. This study explores the adsorption characteristics of
activated carbon on salinizing inorganic salts using isothermal
adsorption experiments and provides a model analysis. The
temperature range for the isothermal adsorption experiments ranged
between 5 to 45 ℃, and the amount adsorbed varied between 28.21 to
33.87 mg/g. All experimental data of adsorption can be fitted to both
the Langmuir and the Freundlich models. The thermodynamic
parameters for per chlorate onto granular activated carbon were
calculated as -0.99 to -1.11 kcal/mol for DG°, -0.6 kcal/mol for DH°,
and 1.21 to 1.84 kcal/mol for DS°. This shows that the adsorption
process of granular activated carbon is spontaneously exothermic. The
observation of adsorption behaviors under low ionic strength, low pH
values, and low temperatures is beneficial to the adsorption removal of
perchlorate with granular activated carbon.