Abstract: Nonlinear finite element method with eight noded
isoparametric quadrilateral element is used for prediction of loaddeformation
behavior including bearing capacity of foundations.
Modified generalized plasticity model with non-associated flow rule
is applied for analysis of soil-footing system. Also Von Mises and
Tresca criterions are used for simulation of soil behavior. Modified
generalized plasticity model is able to simulate load-deformation
including softening behavior. Localization phenomena are considered
by different meshes. Localization phenomena have not been seen in
the examples. Predictions by modified generalized plasticity model
show good agreement with laboratory data and theoretical prediction
in comparison the other models.
Abstract: The adsorption of simulated aqueous solution containing textile remazol reactive dye, namely Red 3BS by palm shell activated carbon (PSAC) as adsorbent was carried out using Response Surface Methodology (RSM). A Box-Behnken design in three most important operating variables; initial dye concentration, dosage of adsorbent and speed of impeller was employed for experimental design and optimization of results. The significance of independent variables and their interactions were tested by means of the analysis of variance (ANOVA) with 95% confidence limits. Model indicated that with the increasing of dosage and speed give the result of removal up to 90% with the capacity uptake more than 7 mg/g. High regression coefficient between the variables and the response (R-Sq = 93.9%) showed of good evaluation of experimental data by polynomial regression model.
Abstract: The radiative exchange method is introduced as a
numerical method for the simulation of radiative heat transfer in an
absorbing, emitting and isotropically scattering media. In this
method, the integro-differential radiative balance equation is solved
by using a new introduced concept for the exchange factor. Even
though the radiative source term is calculated in a mesh structure that
is coarser than the structure used in computational fluid dynamics,
calculating the exchange factor between different coarse elements by
using differential integration elements makes the result of the method
close to that of integro-differential radiative equation. A set of
equations for calculating exchange factors in two and threedimensional
Cartesian coordinate system is presented, and the
method is used in the simulation of radiative heat transfer in twodimensional
rectangular case and a three-dimensional simple cube.
The result of using this method in simulating different cases is
verified by comparing them with those of using other numerical
radiative models.
Abstract: This paper presents a developed method for
controlling multi-renewable energy generators. The control system
depends basically on three sensors (wind anemometer, solar sensor,
and voltage sensor). These sensors represent PLC-s analogue inputs.
Controlling the output voltage supply can be achieved by an
enhanced method of interlocking between the renewable energy
generators, depending on those sensors and output contactors.
Abstract: This paper addresses one important aspect of
combustion system analysis, the spray evaporation and
dispersion modeling. In this study we assume an empty
cylinder which is as a simulator for a ramjet engine and the
cylinder has been studied by cold flow. Four nozzles have the
duties of injection which are located in the entrance of
cylinder. The air flow comes into the cylinder from one side
and injection operation will be done. By changing injection
velocity and entrance air flow velocity, we have studied
droplet sizing and efficient mass fraction of fuel vapor near
and at the exit area. We named the mass of fuel vapor inside
the flammability limit as the efficient mass fraction. Further,
we decreased the initial temperature of fuel droplets and we
have repeated the investigating again. To fulfill the calculation
we used a modified version of KIVA-3V.
Abstract: State-dependent Riccati equation based controllers are
becoming increasingly popular because of having attractive
properties like optimality, stability and robustness. This paper focuses
on the design of a roll autopilot for a fin stabilized and canard
controlled 122mm artillery rocket using state-dependent Riccati
equation technique. Initial spin is imparted to rocket during launch
and it quickly decays due to straight tail fins. After the spin phase, the
roll orientation of rocket is brought to zero with the canard deflection
commands generated by the roll autopilot. Roll autopilot has been
developed by considering uncoupled roll, pitch and yaw channels.
The canard actuator is modeled as a second-order nonlinear system.
Elements of the state weighing matrix for Riccati equation have been
chosen to be state dependent to exploit the design flexibility offered
by the Riccati equation technique. Simulation results under varying
conditions of flight demonstrate the wide operating range of the
proposed autopilot.
Abstract: A Personal Distributed Environment (PDE) is an
example of an IP-based system architecture designed for future
mobile communications. In a single PDE, there exist several Subnetworks
hosting devices located across the infrastructure, which will
inter-work with one another through the coordination of a Device
Management Entity (DME). Some of these Sub-networks are fixed
and some are mobile. In order to support Mobile Sub-networks
mobility in the PDE, the PDE-NEMO protocol was proposed. This
paper discussed the signalling cost analysis of PDE-NEMO by use of
a detailed simulation model. The paper started with the introduction
of the protocol, followed by the experiments and results and then
followed by discussions.
Abstract: A 7-step method (with 25 sub-steps) to assess risk of
air pollutants is introduced. These steps are: pre-considerations,
sampling, statistical analysis, exposure matrix and likelihood, doseresponse
matrix and likelihood, total risk evaluation, and discussion
of findings. All mentioned words and expressions are wellunderstood;
however, almost all steps have been modified, improved,
and coupled in such a way that a comprehensive method has been
prepared. Accordingly, the SADRA (Statistical Analysis-Driven Risk
Assessment) emphasizes extensive and ongoing application of
analytical statistics in traditional risk assessment models. A Sulfur
Dioxide case study validates the claim and provides a good
illustration for this method.
Abstract: Social interest and demand on Home-Network has
been increasing greatly. Although various services are being
introduced to respond to such demands, they can cause serious
security problems when linked to the open network such as Internet.
This paper reviews the security requirements to protect the service
users with assumption that the Home-Network environment is
connected to Internet and then proposes the security model based on
the requirement. The proposed security model can satisfy most of the
requirements and further can be dynamically applied to the future
ubiquitous Home-Networks.
Abstract: A new paradigm for software design and development models software by its business process, translates the model into a process execution language, and has it run by a supporting execution engine. This process-oriented paradigm promotes modeling of software by less technical users or business analysts as well as rapid development. Since business process models may be shared by different organizations and sometimes even by different business domains, it is interesting to apply a technique used in traditional software component technology to design reusable business processes. This paper discusses an approach to apply a technique for software component fabrication to the design of process-oriented software units, called process components. These process components result from decomposing a business process of a particular application domain into subprocesses with an aim that the process components can be reusable in different process-based software models. The approach is quantitative because the quality of process component design is measured from technical features of the process components. The approach is also strategic because the measured quality is determined against business-oriented component management goals. A software tool has been developed to measure how good a process component design is, according to the required managerial goals and comparing to other designs. We also discuss how we benefit from reusable process components.
Abstract: Adsorption of Toluidine blue dye from aqueous solutions onto Neem Leaf Powder (NLP) has been investigated. The surface characterization of this natural material was examined by Particle size analysis, Scanning Electron Microscopy (SEM), Fourier Transform Infrared (FTIR) spectroscopy and X-Ray Diffraction (XRD). The effects of process parameters such as initial concentration, pH, temperature and contact duration on the adsorption capacities have been evaluated, in which pH has been found to be most effective parameter among all. The data were analyzed using the Langmuir and Freundlich for explaining the equilibrium characteristics of adsorption. And kinetic models like pseudo first- order, second-order model and Elovich equation were utilized to describe the kinetic data. The experimental data were well fitted with Langmuir adsorption isotherm model and pseudo second order kinetic model. The thermodynamic parameters, such as Free energy of adsorption (AG"), enthalpy change (AH') and entropy change (AS°) were also determined and evaluated.
Abstract: Chevron frames (Inverted-V-braced frames or Vbraced
frames) have seismic disadvantages, such as not good exhibit force redistribution capability and compression brace buckles
immediately. Researchers developed new design provisions on
increasing both the ductility and lateral resistance of these structures
in seismic areas. One of these new methods is adding zipper columns, as proposed by Khatib et al. (1988) [2]. Zipper columns are
vertical members connecting the intersection points of the braces
above the first floor. In this paper applicability of the suspended
zipper system to Seismic Rehabilitation of Steel Structures is investigated.
The models are 3-, 6-, 9-, and 12-story Inverted-V-braced frames.
In this case, it is assumed that the structures must be rehabilitated. For rehabilitation of structures, zipper column is used. The result of
researches showed that the suspended zipper system is effective in
case of 3-, 6-, and 9-story Inverted-V-braced frames and it would
increase lateral resistance of structure up to life safety level. But in
case of high-rise buildings (such as 12 story frame), it doesn-t show
good performance. For solving this problem, the braced bay can
consist of small “units" over the height of the entire structure, which each of them is a zipper-braced bay with a few stories. By using this
method the lateral resistance of 12 story Inverted-V-braced frames is increased up to safety life level.
Abstract: This article discusses the concept of student ownership of knowledge and seeks to determine how to move students from knowledge acquisition to knowledge application and ultimately to knowledge generation in a virtual setting. Instructional strategies for fostering student engagement in a virtual environment are critical to the learner-s strategic ownership of the knowledge. A number of relevant theories that focus on learning, affect, needs and adult concerns are presented to provide a basis for exploring the transfer of knowledge from teacher to learner. A model under development is presented that combines the dimensions of knowledge approach, the teacher-student relationship with regards to knowledge authority and teaching approach to demonstrate the recursive and scaffolded design for creation of virtual learning environments.
Abstract: MABENA model is a complementary model in
comparison with traditional models such as HCMS, CMS and etc.
New factors, which have effects on preparation of strategic plans and
their sequential order in MABENA model is the platform of
presented road map in this paper.Study review shows, factors such as
emerging new critical success factors for strategic planning,
improvement of international strategic models, increasing the
maturity of companies and emerging new needs leading to design a
new model which can be responsible for new critical factors and
solve the limitations of previous strategic management models.
Preparation of strategic planning need more factors than introduced
in traditional models. The needed factors includes determining future
Critical Success Factors and competencies, defining key processes,
determining the maturity of the processes, considering all aspects of
the external environment etc. Description of aforementioned
requirements, the outcomes and their order is developing and
presenting the MABENA model-s road map in this paper. This study
presents a road map for strategic planning of the Iranian
organizations.
Abstract: Safety of bus journey is a fundamental concern. Risk of injuries and fatalities is severe when bus superstructure fails during rollover accident. Adequate design and sufficient strength of bus superstructure can reduce the number of injuries and fatalities. This paper deals with structural analysis of bus superstructure undergoes rollover event. Several value of mass will be varied in multiple simulations. The purpose of this work is to analyze structural response of bus superstructure in terms of deformation, stress and strain under several loading and constraining conditions. A complete bus superstructure with forty four passenger-s capability was developed using finite element analysis software. Simulations have been conducted to observe the effect of total mass of bus on the strength of superstructure. These simulations are following United Nation Economic Commission of Europe regulation 66 which focuses on strength of large vehicle superstructure. Validation process had been done using simple box model experiment and results obtained are comparing with simulation results. Inputs data from validation process had been used in full scale simulation. Analyses suggested that, the failure of bus superstructure during rollover situation is basically dependent on the total mass of bus and on the strength of bus superstructure.
Abstract: This article stands in the context of rural communities
in Brazil, where, like many others emerging countries, the
overwhelming increasing markets and the overcrowded cities are
leaving behind informal settlements based on obsolete agricultural
economies and techniques. The pilot project for the community of
Goiabeira reflects the attempt to imagine a development model that
privileges the actual improvement of living conditions, the education
and training, the social inclusion and participation of the dwellers of
rural communities. Through the inclusion of operative public space,
the aim is for them to become self-sustaining, encouraging the use of
local resources for appropriate architectural, ecological and energy
technologies and devices, that are efficient, affordable and foster
community participation, in the respect of the surrounding
environment.
Abstract: In this study, a reformer model simulation to use
refinery (Farashband refinery, Iran) waste natural gas. In the
petroleum and allied sectors where natural gas is being encountered
(in form of associated gas) without prior preparation for its positive
use, its combustion (which takes place in flares, an equipment through
which they are being disposed) has become a great problem because
of its associated environmental problems in form of gaseous emission.
The proposed model is used to product syngas from waste natural gas.
A detailed steady model described by a set of ordinary differential and
algebraic equations was developed to predict the behavior of the
overall process. The proposed steady reactor model was validated
against process data of a reformer synthesis plant recorded and a good
agreement was achieved. H2/CO ratio has important effect on Fischer-
Tropsch synthesis reactor product and we try to achieve this parameter
with best designing reformer reactor. We study different kind of
reformer reactors and then select auto thermal reforming process of
natural gas in a fixed bed reformer that adjustment H2/CO ratio with
CO2 and H2O injection. Finally a strategy was proposed for prevention
of extra natural gas to atmosphere.
Abstract: With the growth of electricity generation from gas
energy gas pipeline reliability can substantially impact the electric
generation. A physical disruption to pipeline or to a compressor
station can interrupt the flow of gas or reduce the pressure and lead
to loss of multiple gas-fired electric generators, which could
dramatically reduce the supplied power and threaten the power
system security. Gas pressure drops during peak loading time on
pipeline system, is a common problem in network with no enough
transportation capacity which limits gas transportation and causes
many problem for thermal domain power systems in supplying their
demand. For a feasible generation scheduling planning in networks
with no sufficient gas transportation capacity, it is required to
consider gas pipeline constraints in solving the optimization problem
and evaluate the impacts of gas consumption in power plants on gas
pipelines operating condition. This paper studies about operating of
gas fired power plants in critical conditions when the demand of gas
and electricity peak together. An integrated model of gas and electric
model is used to consider the gas pipeline constraints in the economic
dispatch problem of gas-fueled thermal generator units.
Abstract: The recent developments in computing and
communication technology permit to users to access multimedia
documents with variety of devices (PCs, PDAs, mobile phones...)
having heterogeneous capabilities. This diversification of supports
has trained the need to adapt multimedia documents according to
their execution contexts. A semantic framework for multimedia
document adaptation based on the conceptual neighborhood graphs
was proposed. In this framework, adapting consists on finding
another specification that satisfies the target constraints and which is
as close as possible from the initial document. In this paper, we
propose a new way of building the conceptual neighborhood graphs
to best preserve the proximity between the adapted and the original
documents and to deal with more elaborated relations models by
integrating the relations relaxation graphs that permit to handle the
delays and the distances defined within the relations.
Abstract: Wind power is among the most actively developing distributed generation (DG) technology. Majority of the wind power based DG technologies employ wind turbine induction generators (WTIG) instead of synchronous generators, for the technical advantages like: reduced size, increased robustness, lower cost, and increased electromechanical damping. However, dynamic changes of wind speed make the amount of active/reactive power injected/drawn to a WTIG embedded distribution network highly variable. This paper analyzes the effect of wind speed changes on the active and reactive power penetration to the wind energy embedded distribution network. Four types of wind speed changes namely; constant, linear change, gust change and random change of wind speed are considered in the analysis. The study is carried out by three-phase, non-linear, dynamic simulation of distribution system component models. Results obtained from the investigation are presented and discussed.