Abstract: Science and technology of ultrasonic is widely used in
recent years for industrial and medicinal application. The acoustical
properties of 2-mercapto substituted pyrimidines viz.,2- Mercapto-4-
(2’,4’ –dichloro phenyl) – 6-(2’ – hydroxyl -4’ –methyl-5’ –
chlorophenyl) pyrimidine and 2 –Mercapto – 4-(4’ –chloro phenyl) –
6-(2’ – hydroxyl -4’ –methyl-5’ –chlorophenyl) pyrimidine have been
investigated from the ultrasonic velocity and density measurements at
different concentration and different % in dioxane-water mixture at
305K. The adiabatic compressibility (βs), acoustic impedance (Z),
intermolecular free length (Lf), apparent molar volume(ϕv) and
relative association (RA) values have been calculated from the
experimental data of velocity and density measurement at
concentration range of 0.01- 0.000625 mol/lit and 70%,75% and 80%
dioxane water mixture. These above parameters are used to discuss
the structural and molecular interactions.
Abstract: This paper investigates the effectiveness of the use of
seismic isolation devices on the overall 3D seismic response of
curved highway viaducts with an emphasis on expansion joints.
Furthermore, an evaluation of the effectiveness of the use of cable
restrainers is presented. For this purpose, the bridge seismic
performance has been evaluated on four different radii of curvature,
considering two cases: restrained and unrestrained curved viaducts.
Depending on the radius of curvature, three-dimensional non-linear
dynamic analysis shows the vulnerability of curved viaducts to
pounding and deck unseating damage. In this study, the efficiency of
using LRB supports combined with cable restrainers on curved
viaducts is demonstrated, not only by reducing in all cases the
possible damage, but also by providing a similar behavior in the
viaducts despite of curvature radius.
Abstract: Positioning the organization in the strategic
environment of its industry is one of the first and most important
phases of the organizational strategic planning and in today
knowledge-based economy has its importance been duplicated for
higher education institutes as the centers of education, knowledge
creation and knowledge worker training. Up to now, various models
with diverse approaches have been applied to investigate
organizations- strategic position in different industries. Regarding the
essential importance and strategic role of quality in higher education
institutes, in this study, a quality-oriented approach has been
suggested to positioning them in their strategic environment. Then
the European Foundation of Quality Management (EFQM) model has
been adopted to position the top Iranian business schools in their
strategic environment. The result of this study can be used in strategic
planning of these institutes as well as the other Iranian business
schools.
Abstract: The regulatory competence of blood glucose homeostasis might determine the degree of academic performance. The aim of this study was to produce a model of students' alcohol use based on glucose homeostasis control and cognitive functions that might define the pathogenetic mechanism of alcohol's effect on academic performance. The study took six hours and thirty minutes on fasting, involving thirteen male students. Disturbances in cognitive functions, precisely a decrease in the effectiveness of active attention and a faster development of fatigue after four to six hours of mental work in alcohol users, compared to abstainers was statistically proven. These disturbances in alcohol users were retained even after seven to ten days of moderate alcohol use and might be the reason for the low academic performances among students who use alcoholic beverages.
Abstract: A numerical study is presented on convective heat transfer in enclosures. The results are addressed to automotive headlights containing new-age light sources like Light Emitting Diodes (LED). The heat transfer from the heat source (LED) to the enclosure walls is investigated for mixed convection as interaction of the forced convection flow from an inlet and an outlet port and the natural convection at the heat source. Unlike existing studies, inlet and outlet port are thermally coupled and do not serve to remove hot fluid. The input power of the heat source is expressed by the Rayleigh number. The internal position of the heat source, the aspect ratio of the enclosure, and the inclination angle of one wall are varied. The results are given in terms of the global Nusselt number and the enclosure Nusselt number that characterize the heat transfer from the source and from the interior fluid to the enclosure walls, respectively. It is found that the heat transfer from the source to the fluid can be maximized if the source is placed in the main stream from the inlet to the outlet port. In this case, the Reynolds number and heat source position have the major impact on the heat transfer. A disadvantageous position has been found where natural and forced convection compete each other. The overall heat transfer from the source to the wall increases with increasing Reynolds number as well as with increasing aspect ratio and decreasing inclination angle. The heat transfer from the interior fluid to the enclosure wall increases upon decreasing the aspect ratio and increasing the inclination angle. This counteracting behaviour is caused by the variation of the area of the enclosure wall. All mixed convection results are compared to the natural convection limit.
Abstract: This paper presents a new method of fault detection and isolation (FDI) for polymer electrolyte membrane (PEM) fuel cell (FC) dynamic systems under an open-loop scheme. This method uses a radial basis function (RBF) neural network to perform fault identification, classification and isolation. The novelty is that the RBF model of independent mode is used to predict the future outputs of the FC stack. One actuator fault, one component fault and three sensor faults have been introduced to the PEMFC systems experience faults between -7% to +10% of fault size in real-time operation. To validate the results, a benchmark model developed by Michigan University is used in the simulation to investigate the effect of these five faults. The developed independent RBF model is tested on MATLAB R2009a/Simulink environment. The simulation results confirm the effectiveness of the proposed method for FDI under an open-loop condition. By using this method, the RBF networks able to detect and isolate all five faults accordingly and accurately.
Abstract: In this paper we define generalized differential operators from some well-known operators on the class A of analytic functions in the unit disk U = {z ∈ C : |z| < 1}. New classes containing these operators are investigated. Also univalence of integral operator is considered.
Abstract: A conjugate heat transfer for steady two-dimensional
mixed convection with magnetic hydrodynamic (MHD) flow of an
incompressible quiescent fluid over an unsteady thermal forming
stretching sheet has been studied. A parameter, M, which is used to
represent the dominance of the magnetic effect has been presented in
governing equations. The similar transformation and an implicit
finite-difference method have been used to analyze the present
problem. The numerical solutions of the flow velocity distributions,
temperature profiles, the wall unknown values of f''(0) and '(θ (0) for
calculating the heat transfer of the similar boundary-layer flow are
carried out as functions of the unsteadiness parameter (S), the Prandtl
number (Pr), the space-dependent parameter (A) and
temperature-dependent parameter (B) for heat source/sink and the
magnetic parameter (M). The effects of these parameters have also
discussed. At the results, it will produce greater heat transfer effect
with a larger Pr and M, S, A, B will reduce heat transfer effects. At
last, conjugate heat transfer for the free convection with a larger G has
a good heat transfer effect better than a smaller G=0.
Abstract: In recent years the large scale use of the power electronic equipment has led to an increase of harmonics in the power system. The harmonics results into a poor power quality and have great adverse economical impact on the utilities and customers. Current harmonics are one of the most common power quality problems and are usually resolved by using shunt active filter (SHAF). The main objective of this work is to develop PI and Fuzzy logic controllers (FLC) to analyze the performance of Shunt Active Filter for mitigating current harmonics under balanced and unbalanced sinusoidal source voltage conditions for normal load and increased load. When the supply voltages are ideal (balanced), both PI and FLC are converging to the same compensation characteristics. However, the supply voltages are non-ideal (unbalanced), FLC offers outstanding results. Simulation results validate the superiority of FLC with triangular membership function over the PI controller.
Abstract: Experiments with pumpkin-rowanberry marmalade
candies were carried out at the Faculty of Food Technology of the
Latvia University of Agriculture. The objective of this investigation
was to evaluate the quality changes of pumpkin-rowanberry
marmalade candies packed in different packaging materials during
the storage of 15 weeks, and to find the most suitable packaging
material for prolongation of low sugar marmalade candies shelf-life.
An active packaging in combination with modified atmosphere
(MAP, CO2 100%) was examined and compared with traditional
packaging in air ambiance. Polymer Multibarrier 60 and paper bags
were used. Influence of iron based oxygen absorber in sachets of 500
cc obtained from Mitsubishi Gas Chemical Europe Ageless® on the
marmalade candies’ quality was tested during shelf life. Samples of
80±5 g were packaged in polymer pouches (110 mm x 110 mm),
hermetically sealed by MULTIVAC C300 vacuum chamber machine,
and stored in a room temperature +21±0.5 °C. The physiochemical
properties –moisture content, hardness, aw, pH, changes of
atmosphere content (CO2 and O2), ascorbic acid, total carotenoids,
total phenols in headspace of packs, and microbial conditions were
analysed before packaging and in the 1st, 3rd , 5th, 8th, 11th and 15th
weeks of storage.
Abstract: Nowadays, the earth is countered with serious problem
of air pollution. This problem has been started from the industrial
revolution and has been faster in recent years, so that leads the earth
to ecological and environmental disaster. One of its results is the
global warming problem and its related increase in global
temperature. The most important factors in air pollution especially in
urban environments are Automobiles and residential buildings that are
the biggest consumers of the fossil energies, so that if the residential
buildings as a big part of the consumers of such energies reduce their
consumption rate, the air pollution will be decreased. Since
Metropolises are the main centers of air pollution in the world,
assessment and analysis of efficient strategies in decreasing air
pollution in such cities, can lead to the desirable and suitable results
and can solve the problem at least in critical level. Tabriz city is one
of the most important metropolises in North west of Iran that about
two million people are living there. for its situation in cold dry
climate, has a high rate of fossil energies consumption that make air
pollution in its urban environment. These two factors, being both
metropolis and in cold dry climate, make this article try to analyze the
strategies of climatic design in old districts of the city and use them in
new districts of the future. These strategies can be used in this city
and other similar cities and pave the way to reduce energy
consumption and related air pollution to save whole world.
Abstract: This paper proposes a novel solution for optimizing
the size and communication overhead of a distributed multiagent
system without compromising the performance. The proposed approach
addresses the challenges of scalability especially when the
multiagent system is large. A modified spectral clustering technique
is used to partition a large network into logically related clusters.
Agents are assigned to monitor dedicated clusters rather than monitor
each device or node. The proposed scalable multiagent system is
implemented using JADE (Java Agent Development Environment)
for a large power system. The performance of the proposed topologyindependent
decentralized multiagent system and the scalable multiagent
system is compared by comprehensively simulating different
fault scenarios. The time taken for reconfiguration, the overall computational
complexity, and the communication overhead incurred are
computed. The results of these simulations show that the proposed
scalable multiagent system uses fewer agents efficiently, makes faster
decisions to reconfigure when a fault occurs, and incurs significantly
less communication overhead.
Abstract: Nowadays, access to sustainable development in cities is assumed as one of the most important goals of urban managers. In the meanwhile, neighborhood as the smallest unit of urban spatial organization has a substantial effect on urban sustainability. Hence, attention to and focus on this subject is highly important in urban development plans. The objective of this study is evaluation of the status of Jahanshahr Neighborhood in Karaj city based on sustainable neighborhood development indicators. This research has been applied based on documentary method and field surveys. Also, evaluating of Jahanshahr Neighborhood of Karaj shows that it has a high level in sustainability in physical and economical dimension while a low level in cultural and social dimension. For this purpose, this neighborhood as a semi-sustainable neighborhood must take measures for development of collective spaces and efficiency of utilizing the public neighborhood spaces via collaboration of citizens and officials.
Abstract: A numerical study has been carried out to investigate
the heat transfer by natural convection of nanofluid taking Cu as
nanoparticles and the water as based fluid in a three dimensional
annulus enclosure filled with porous media (silica sand) between two
horizontal concentric cylinders with 12 annular fins of 2.4mm
thickness attached to the inner cylinder under steady state conditions.
The governing equations which used are continuity, momentum and
energy equations under an assumptions used Darcy law and
Boussinesq-s approximation which are transformed to dimensionless
equations. The finite difference approach is used to obtain all the
computational results using the MATLAB-7. The parameters affected
on the system are modified Rayleigh number (10 ≤Ra*≤ 1000), fin
length Hf (3, 7 and 11mm), radius ratio Rr (0.293, 0.365 and 0.435)
and the volume fraction(0 ≤ ¤ò ≤ 0 .35). It was found that the
average Nusselt number depends on (Ra*, Hf, Rr and φ). The results
show that, increasing of fin length decreases the heat transfer rate and
for low values of Ra*, decreasing Rr cause to decrease Nu while for
Ra*
greater than 100, decreasing Rr cause to increase Nu and adding
Cu nanoparticles with 0.35 volume fraction cause 27.9%
enhancement in heat transfer. A correlation for Nu in terms of Ra*,
Hf and φ, has been developed for inner hot cylinder.
Abstract: This paper proposes a simple model of economic geography within the Dixit-Stiglitz-Iceberg framework that may be used to analyze migration patterns among three cities. The cost–benefit tradeoffs affecting incentives for three types of migration, including echelon migration, are discussed. This paper develops a tractable, heterogeneous-agent, general equilibrium model, where agents share constant human capital, and explores the relationship between the benefits of echelon migration and gross human capital. Using Chinese numerical solutions, we study the manifestation of echelon migration and how it responds to changes in transportation cost and elasticity of substitution. Numerical results demonstrate that (i) there are positive relationships between a migration-s benefit-and-wage ratio, (ii) there are positive relationships between gross human capital ratios and wage ratios as to origin and destination, and (iii) we identify 13 varieties of human capital convergence among cities. In particular, this model predicts population shock resulting from the processes of migration choice and echelon migration.
Abstract: In this paper, an analytical approach for free vibration
analysis of four edges simply supported rectangular Kirchhoff plates
is presented. The method is based on wave approach. From wave
standpoint vibration propagate, reflect and transmit in a structure.
Firstly, the propagation and reflection matrices for plate with simply
supported boundary condition are derived. Then, these matrices are
combined to provide a concise and systematic approach to free
vibration analysis of a simply supported rectangular Kirchhoff plate.
Subsequently, the eigenvalue problem for free vibration of plates is
formulated and the equation of plate natural frequencies is
constructed. Finally, the effectiveness of the approach is shown by
comparison of the results with existing classical solution.
Abstract: The Kowsar dam supply water for different usages
such as drinking, industrial, agricultural and aquaculture farms
usages and located next to the city of Dehdashat in Kohgiluye and
Boyerahmad province in southern Iran. There are some towns and
villages on the Kowsar dam watersheds, which Dehdasht and
Choram are the most important and populated cities in this area. The
study was undertaken to assess the status of water quality in the
urban areas of the Kowsar dam. A total of 28 water samples were
collected from 6 stations on surface water and 1 station from
groundwater on the watershed of the Kowsar dam. All the samples
were analyzed for Cd concentration using standard procedures. The
results were compared with other national and international
standards. Among the analyzed samples, as the maximum value of
cadmium (1.131 μg/L) was observed on the station 2 at the winter
2009, all the samples analyzed were within the maximum admissible
limits by the United States Environmental Protection Agency, EU,
WHO, New Zealand , Australian, Iranian, and the Indian standards.
In general results of the present study have shown that Cd mean
values of stations No. 4, 1 and 2 with 0.5135, 0.0.4733 and 0.4573
μg/L respectively are higher than the other stations . Although Cd
level of all samples and stations have had normal values but this is
an indication of pollution potential and hazards because of human
activity and waste water of towns in the areas, which can effect on
human health implications in future. This research, therefore,
recommends the government and other responsible authorities to take
suitable improving measures in the Kowsar dam watershed-s.
Abstract: The spores of entomopathogenic fungi, Beauveria bassiana was evaluated for their compatibility with four surfactants; SDS (sodium dodyl sulphate) and CABS-65 (calcium alkyl benzene sulphonate), Tween 20 (polyethylene sorbitan monolaureate) and Tween 80 (polyoxyethylene sorbitan monoleate) at six different concentrations (0.1%, 0.5%, 1%, 2.5%, 5% and 10%). Incubated spores showed decrease in concentrations due to conversion of spores to hyphae. The maximum germination recorded in 72 h incubated spores varied with surfactant concentration at 49-68% (SDS), 39- 53% (CABS), 78-92% (Tween 80) and 80-92% (Tween 20), while the optimal surfactant concentration for spore germination was found to be 2.5-5%. The surfactant effect on spores was more pronounced with SDS and CABS-65, where significant deterioration and loss in viability of the incubated spores was observed. The effect of Tween 20 and Tween 80 were comparatively less inhibiting. The results of the study would help in surfactant selection for B. bassiana emulsion preparation.
Abstract: Sorting appears the most attention among all computational tasks over the past years because sorted data is at the heart of many computations. Sorting is of additional importance to parallel computing because of its close relation to the task of routing data among processes, which is an essential part of many parallel algorithms. Many parallel sorting algorithms have been investigated for a variety of parallel computer architectures. In this paper, three parallel sorting algorithms have been implemented and compared in terms of their overall execution time. The algorithms implemented are the odd-even transposition sort, parallel merge sort and parallel rank sort. Cluster of Workstations or Windows Compute Cluster has been used to compare the algorithms implemented. The C# programming language is used to develop the sorting algorithms. The MPI (Message Passing Interface) library has been selected to establish the communication and synchronization between processors. The time complexity for each parallel sorting algorithm will also be mentioned and analyzed.
Abstract: A Rotary Disc Contactor with inner diameter of
9.1cm and maximum operating height of 40cm has been used to
investigate break up phenomenon. Water-Toluene, Water as
continuous phase and Toluene as dispersed phase, was selected as
chemical system in the experiments. The mentioned chemical system
has high interfacial tension so it was possible to form big drops
which permit accurate investigation on break up phenomenon as well
as the first and second critical rotor speeds.
In this study, Break up phenomenon has been studied as a function
of mother drop size, rotor speed and continuous phase height. Further
more; the effects of mother drop size and continuous phase height on
the first and second critical rotor speeds were investigated. Finally,
two modified correlations were proposed to estimate the first and
second critical speeds.