Abstract: In order to enhance the aircraft survivability, the
infrared signatures emitted by hot engine parts should be determined
exactly. For its reduction it is necessary for the rear fuselage
temperature to be decreased. In this study, numerical modeling of flow
fields and heat transfer characteristics of an aircraft nozzle is
performed and its temperature distribution along each component wall
is predicted. The radiation shield is expected to reduce the skin
temperature of rear fuselage. The effect of material characteristic of
radiation shield on the heat transfer is also investigated. Through this
numerical analysis, design parameters related to the susceptibility of
aircraft are examined.
Abstract: This paper addresses the problem of trajectory
tracking control of an underactuated autonomous underwater vehicle
(AUV) in the horizontal plane. The underwater vehicle under
consideration is not actuated in the sway direction, and the system
matrices are not assumed to be diagonal and linear, as often found in
the literature. In addition, the effect of constant bias of environmental
disturbances is considered. Using backstepping techniques and the
tracking error dynamics, the system states are stabilized by forcing
the tracking errors to an arbitrarily small neighborhood of zero. The
effectiveness of the proposed control method is demonstrated through
numerical simulations. Simulations are carried out for an
experimental vehicle for smooth, inertial, two dimensional (2D)
reference trajectories such as constant velocity trajectory (a circle
maneuver – constant yaw rate), and time varying velocity trajectory
(a sinusoidal path – sinusoidal yaw rate).
Abstract: This work presents a comparison between the Annual
Energy Output (AEO) of two commercial vertical-axis wind turbines
(VAWTs) for a low-wind urban site: both a drag-driven and a liftdriven
concepts are examined in order to be installed on top of the
new Via dei Giustinelli building, Trieste (Italy). The power-curves,
taken from the product specification sheets, have been matched to the
wind characteristics of the selected installation site. The influence of
rotor swept area and rated power on the performance of the two
proposed wind turbines have been examined in detail, achieving a
correlation between rotor swept area, electrical generator size and
wind distribution, to be used as a guideline for the calculation of the
AEO.
Abstract: Subsonic wind tunnel experiments were conducted to
study the effect of tripped boundary layer on the pressure distribution
in the contraction region of the tunnel. Measurements were
performed by installing trip strip at two different positions in the
concave portion of the contraction. The results show that installation
of the trip strips, have significant effects on both turbulence and
pressure distribution. The reduction in the free stream turbulence and
reduction of the wall static pressure distribution deferred signified
with the location of the trip strip.
Abstract: This purpose of this paper is to present the acceptance single sampling plan when the fraction of nonconforming items is a fuzzy number and being modeled based on the fuzzy Poisson distribution. We have shown that the operating characteristic (oc) curves of the plan is like a band having a high and low bounds whose width depends on the ambiguity proportion parameter in the lot when that sample size and acceptance numbers is fixed. Finally we completed discuss opinion by a numerical example. And then we compared the oc bands of using of binomial with the oc bands of using of Poisson distribution.
Abstract: An exact algorithm for a n-link manipulator movement amidst arbitrary unknown static obstacles is presented.
The algorithm guarantees the reaching of a target configuration of the manipulator in a finite number of steps. The algorithm is
reduced to a finite number of calls of a subroutine for planning a trajectory in the presence of known forbidden states. The polynomial approximation algorithm which is used as the subroutine is presented. The results of the exact algorithm
implementation for the control of a seven link (7 degrees of
freedom, 7DOF) manipulator are given.
Abstract: The unique structural configuration found in human foot allows easy walking. Similar movement is hard to imitate even for an ape. It is obvious that human ambulation relates to the foot structure itself. Suppose the bones are represented as vertices and the joints as edges. This leads to the development of a special graph that represents human foot. On a footprint there are point-ofcontacts which have contact with the ground. It involves specific vertices. Theoretically, for an ideal ambulation, these points provide reactions onto the ground or the static equilibrium forces. They are arranged in sequence in form of a path. The ambulating footprint follows this path. Having the human foot graph and the path crossbred, it results in a representation that describes the profile of an ideal ambulation. This profile cites the locations where the point-of-contact experience normal reaction forces. It highlights the significant of these points.
Abstract: BEAMnrc was used to calculate the spectrum and
HVL for X-ray Beam during low energy X-ray radiation using tube model: SRO 33/100 /ROT 350 Philips. The results of BEAMnrc
simulation and measurements were compared to the IPEM report
number 78 and SpekCalc software. Three energies 127, 103 and 84
Kv were used. In these simulation a tungsten anode with 1.2 mm for
Be window were used as source. HVLs were calculated from
BEAMnrc spectrum with air Kerma method for four different filters.
For BEAMnrc one billion particles were used as original particles for
all simulations. The results show that for 127 kV, there was
maximum 5.2 % difference between BEAMnrc and Measurements
and minimum was 0.7% .the maximum 9.1% difference between
BEAMnrc and IPEM and minimum was 2.3% .The maximum
difference was 3.2% between BEAMnrc and SpekCal and minimum
was 2.8%. The result show BEAMnrc was able to satisfactory predict
the quantities of Low energy Beam as well as high energy X-ray
radiation.
Abstract: The aim of this study was to examine and identify the
type of Iranian financial market in terms of being symmetrical or
asymmetrical and to measure relationship between type of market
and the market's indices. In this study, daily information on the
market-s Share Price Index, Industrial Index and Top Fifty Most
Active Companies during the years 1999-2010 has been used. In
addition, to determine type of the financial market, rate of return on
Security is taken into account. In this research, by using logistic
regression analysis methods, relationship of the market type with the
above mentioned indices have been examined. The results showed
that the type of the financial market has a positive significant
association with market share price index and Industrial Index. Index
of Top Fifty Most Active Companies is significantly associated with
type of financial market, however this relationship is inverse.
Abstract: This study aims to assess the environmental hazards
from radon exhalation rate in the soil samples in selected locations in
Iraqi Kurdistan, using passive (CR-39NTDs) and active (RAD7)
detecting method. Radon concentration, effective radium content and
radon exhalation rate were estimated in soil samples that collected at
the depth level of 30 cm inside 124 houses. The results show that the
emanation rate for radon gas was variation from location to other,
depending on the geological formation. Most health risks come from
emanation of radon and its daughter due to its contribution for indoor
radon, so the results showed that there is a linear relationship
between the ratio of soil and indoor radon concentration (CSoil Rn222/
Cindoor Rn222) and the effective radium content in soil samples. The
results show that radon concentration has high and low values in
Hajyawa city and Er. Tyrawa Qr, respectively. A comparison
between our results with that mentioned in international reports was
done.
Abstract: In order to evaluate the Effects of dual inoculation of
Azotobacter and Mycorrhiza with Nitrogen and Phosphorus levels on
yield and yield components of spring safflower, this study was
carried out in field of Farahan university in Markazi province in
2007. A factorial in a randomized complete block design with three
replications was used inoculation of Azotobacter (with inoculation
and without inoculation) and Mycorrhiza (with inoculation and
without inoculation ) with Nitrogen and Phosphorus levels [F0= N0+
P0 (kg.ha-1), F1= N50+ P25(kg.ha-1), F2= N100+ P50(kg.ha-1) and
F3= N150+ P75 (kg.ha-1)] on spring safflower (cultivar IL-111). In
this study characteristics such as: Harvest index, Hectolitre weight,
Root dry weight, Seed yield, Mycorrhizal Colonization Root,
Number of days to maturity were assessed. Results indicated that
treatment (A0M1F3) with grain yield (1556 kg.ha-1) and treatment
(A0M1F0) with grain yield (918 kg.ha-1) were significantly superior
to the other treatments and according to calculated, inoculation seeds
in plantig date with Azotobacter and Mycorrhiza to cause increase
grain yield about 5/38 percentage. we can by inoculation safflower
seeds with Azotobacter and Mycorrhiza too easily at the time sowing
date. The purpose of this research, study and evaluation the role of
biological fixation N and P, to provide for feeds plants.
Abstract: The experimental results on combustion of rice husk
in a conical fluidized bed combustor (referred to as the conical FBC)
using silica sand as the bed material are presented in this paper. The
effects of excess combustion air and combustor loading as well as the
sand bed height on the combustion pattern in FBC were investigated.
Temperatures and gas concentrations (CO and NO) along over the
combustor height as well as in the flue gas downstream from the ash
collecting cyclone were measured. The results showed that the axial
temperature profiles in FBC were explicitly affected by the
combustor loading whereas the excess air and bed height were found
to have minor influences on the temperature pattern. Meanwhile, the
combustor loading and the excess air significantly affected the axial
CO and NO concentration profiles; however, these profiles were
almost independent of the bed height. The combustion and thermal
efficiencies for this FBC were quantified for different operating
conditions.
Abstract: Grid environments consist of the volatile integration
of discrete heterogeneous resources. The notion of the Grid is to
unite different users and organisations and pool their resources into
one large computing platform where they can harness, inter-operate,
collaborate and interact. If the Grid Community is to achieve this
objective, then participants (Users and Organisations) need to be
willing to donate or share their resources and permit other
participants to use their resources. Resources do not have to be
shared at all times, since it may result in users not having access to
their own resource. The idea of reward-based computing was
developed to address the sharing problem in a pragmatic manner.
Participants are offered a reward to donate their resources to the
Grid. A reward may include monetary recompense or a pro rata share
of available resources when constrained. This latter point may imply
a quality of service, which in turn may require some globally agreed
reservation mechanism. This paper presents a platform for economybased
computing using the WebCom Grid middleware. Using this
middleware, participants can configure their resources at times and
priority levels to suit their local usage policy. The WebCom system
accounts for processing done on individual participants- resources
and rewards them accordingly.
Abstract: Leprosy is an infectious disease caused by
Mycobacterium Leprae, this disease, generally, compromises
the neural fibers, leading to the development of disability.
Disabilities are changes that limit daily activities or social life
of a normal individual. When comes to leprosy, the study of
disability considered the functional limitation (physical
disabilities), the limitation of activity and social participation,
which are measured respectively by the scales: EHF, SALSA
and PARTICIPATION SCALE. The objective of this work is
to propose an on-line monitoring of leprosy patients, which is
based on information scales EHF, SALSA and
PARTICIPATION SCALE. It is expected that the proposed
system is applied in monitoring the patient during treatment
and after healing therapy of the disease. The correlations that
the system is between the scales create a variety of
information, presented the state of the patient and full of
changes or reductions in disability. The system provides
reports with information from each of the scales and the
relationships that exist between them. This way, health
professionals, with access to patient information, can
intervene with techniques for the Prevention of Disability.
Through the automated scale, the system shows the level of
the patient and allows the patient, or the responsible, to take a
preventive measure. With an online system, it is possible take
the assessments and monitor patients from anywhere.
Abstract: WikID is a wiki for industrial design engineers. An
important aspect for the viability of a wiki is the loyalty of the user
community to share their information and knowledge by adding this
knowledge to the wiki. For the initiators of a wiki it is therefore
important to use every aspect to stimulate the user community to
actively participate. In this study the focus is on the styling of the
website. The central question is: How could the WikID website be
visually designed to achieve a user experience which will incite the
user to actively participate in the WikID community? After a
literature study on the influencing factors of a website, a new
interface has been designed by applying the rules found, in order to
expand this website-s active user community. An online
questionnaire regarding the old or the new website gave insights in
the opinions of users. As expected, the new website was rated more
positively than the old website. However, the differences are limited.
Abstract: Temperature, humidity and precipitation in an area,
are parameters proved influential in the climate of that area, and one
should recognize them so that he can determine the climate of that
area. Climate changes are of primary importance in climatology, and
in recent years, have been of great concern to researchers and even
politicians and organizations, for they can play an important role in
social, political and economic activities. Even though the real cause
of climate changes or their stability is not yet fully recognized, they
are a matter of concern to researchers and their importance for
countries has prompted them to investigate climate changes in
different levels, especially in regional, national and continental level.
This issue has less been investigated in our country. However, in
recent years, there have been some researches and conferences on
climate changes. This study is also in line with such researches and
tries to investigate and analyze the trends of climate changes
(temperature and precipitation) in Sefid-roud (the name of a river)
basin. Three parameters of mean annual precipitation, temperature,
and maximum and minimum temperatures in 36 synoptic and
climatology stations in a statistical period of 49 years (1956-2005) in
the stations of Sefid-roud basin were analyzed by Mann-Kendall test.
The results obtained by data analysis show that climate changes are
short term and have a trend. The analysis of mean temperature
revealed that changes have a significantly rising trend, besides the
precipitation has a significantly falling trend.
Abstract: The production of biodiesel from crude palm oil with
a homogeneous base catalyst is unlikely owing to considerable
formation of soap. Free fatty acids (FFA) in crude palm oil need to
be reduced, e.g. by esterification. This study investigated the activity
of sulfated zirconia calcined at various temperatures for esterification
of FFA in crude palm oil to biodiesel. It was found that under a
proper reaction condition, sulfated zirconia well catalyzes
esterification. FFA content can be reduced to an acceptable value for
typical biodiesel production with a homogeneous base catalyst.
Crystallinity and sulfate attachment of sulfated zirconia depend on
calcination temperature during the catalyst preparation. Too low
temperature of calcination gives amorphous sulfated zirconia which
has low activity for esterification of FFA. In contrast, very high
temperature of calcination removes sulfate group, consequently,
conversion of FFA is reduced. The appropriate temperature range of
calcination is 550-650 oC.
Abstract: Deflocculation and gel characterization were
investigated for three different composition of porcelain slips at
specific gravity 1.8. The suspensions were dispersed with sodium
silicate (Na2SiO3) in under-deflocculated slips and fully deflocculated
slips. The rheology characterization of slips was conducted by the
deflocculation curves and the gel curves. The results showed that
decreasing the amount of the ball clay composition in the slips
consumed less dosages of the dispersants. The under-deflocculated
slips tended to have a gelation rate faster than the fully deflocculated
slips.
Abstract: A new Feed-Forward/Feedback Generalized
Minimum Variance Pole-placement Controller to incorporate the
robustness of classical pole-placement into the flexibility of
generalized minimum variance self-tuning controller for Single-Input
Single-Output (SISO) has been proposed in this paper. The design,
which provides the user with an adaptive mechanism, which ensures
that the closed loop poles are, located at their pre-specified positions.
In addition, the controller design which has a feed-forward/feedback
structure overcomes the certain limitations existing in similar poleplacement
control designs whilst retaining the simplicity of
adaptation mechanisms used in other designs. It tracks set-point
changes with the desired speed of response, penalizes excessive
control action, and can be applied to non-minimum phase systems.
Besides, at steady state, the controller has the ability to regulate the
constant load disturbance to zero. Example simulation results using
both simulated and real plant models demonstrate the effectiveness of
the proposed controller.
Abstract: The purpose of the present work was to study the
production and process parameters optimization for the synthesis of
cellulase from Trichoderma viride in solid state fermentation (SSF)
using an agricultural wheat straw as substrates; as fungal conversion
of lignocellulosic biomass for cellulase production is one among the
major increasing demand for various biotechnological applications.
An optimization of process parameters is a necessary step to get
higher yield of product. Several kinetic parameters like pretreatment,
extraction solvent, substrate concentration, initial moisture content,
pH, incubation temperature and inoculum size were optimized for
enhanced production of third most demanded industrially important
cellulase. The maximum cellulase enzyme activity 398.10±2.43
μM/mL/min was achieved when proximally analyzed lignocellulosic
substrate wheat straw inocubated at 2% HCl as pretreatment tool
along with distilled water as extraction solvent, 3% substrate
concentration 40% moisture content with optimum pH 5.5 at 45°C
incubation temperature and 10% inoculum size.