Abstract: Heavy rainfall greatly affects the aerodynamic performance of the aircraft. There are many accidents of aircraft caused by aerodynamic efficiency degradation by heavy rain.
In this Paper we have studied the heavy rain effects on the aerodynamic efficiency of cambered NACA 64-210 and symmetric
NACA 0012 airfoils. Our results show significant increase in drag and decrease in lift. We used preprocessing software gridgen for creation of geometry and mesh, used fluent as solver and techplot as postprocessor. Discrete phase modeling called DPM is used to model the rain particles using two phase flow approach. The rain particles are assumed to be inert.
Both airfoils showed significant decrease in lift and increase in drag in simulated rain environment. The most significant difference between these two airfoils was the NACA 64-210 more sensitivity than NACA 0012 to liquid water content (LWC). We believe that the results showed in this paper will be useful for the designer of the commercial aircrafts and UAVs, and will be helpful for training of the pilots to control the airplanes in heavy rain.
Abstract: Geometry optimizations of metal complexes of Salen(bis(Salicylidene)1,2-ethylenediamine) were carried out at HF and DFT methods employing Lanl2DZ basis set. In this work structural, energies, bond lengths and other physical properties between Mn2+,Cu2+ and Ni2+ ions coordinated by salen–type ligands are examined. All calculations were performed using Gaussian 98W program series. To investigate local aromaticities, NICS were calculated at all centers of rings. The higher the band gap indicating a higher global aromaticity. The possible binding energies have been evaluated. We have evaluated Frequencies and Zero-point energy with freq calculation. The NICS(Nucleous Independent Chemical Shift) Results show Ni(II) complexes are antiaromatic and aromaticites of Mn(II) complexes are larger than Cu(II) complexes. The energy Results show Cu(II) complexes are stability than Mn(II) and Ni(II) complexes.
Abstract: In the present research, a finite element model is
presented to study the geometrical and material nonlinear behavior of
reinforced concrete plane frames considering soil-structure
interaction. The nonlinear behaviors of concrete and reinforcing steel
are considered both in compression and tension up to failure. The
model takes account also for the number, diameter, and distribution
of rebar along every cross section. Soil behavior is taken into
consideration using four different models; namely: linear-, nonlinear
Winkler's model, and linear-, nonlinear continuum model. A
computer program (NARC) is specially developed in order to
perform the analysis. The results achieved by the present model show
good agreement with both theoretical and experimental published
literature. The nonlinear behavior of a rectangular frame resting on
soft soil up to failure using the proposed model is introduced for
demonstration.
Abstract: In the analysis of structures, the nonlinear effects due to large displacement, large rotation and materially-nonlinear are very important and must be considered for the reliable analysis. The non-linear fmite element analysis has potential as usable and reliable means for analyzing of civil structures with the availability of computer technology. In this research the large displacements and materially nonlinear behavior of shear wall is presented with developing of fmite element code using the standard Galerkin weighted residual formulation. Two-dimensional plane stress model was carried out to present the shear wall response. Total Lagangian formulation, which is computationally more effective, is used in the formulation of stiffness matrices and the Newton-Raphson method is applied for the solution of nonlinear transient equations. The details of the program formulation are highlighted and the results of the analyses are presented, along with a comparison of the response of the structure with Ansys software results. The presented model in this paper can be developed for nonlinear analysis of civil engineering structures with different material behavior and complicated geometry.
Abstract: Knowledge of factors, which influence stress and its
distribution, is of key importance to the successful production of
durable restorations. One of this is the marginal geometry. The
objective of this study was to evaluate, by finite element analysis
(FEA), the influence of different marginal designs on the stress
distribution in teeth prepared for cast metal crowns. Five margin
designs were taken into consideration: shoulderless, chamfer,
shoulder, sloped shoulder and shoulder with bevel. For each kind of
preparation three dimensional finite element analyses were initiated.
Maximal equivalent stresses were calculated and stress patterns were
represented in order to compare the marginal designs. Within the
limitation of this study, the shoulder and beveled shoulder margin
preparations of the teeth are preferred for cast metal crowns from
biomechanical point of view.
Abstract: in dissimilar material joints, failure often occurs
along the interface between two materials due to stress singularity.
Stress distribution and its concentration depend on materials and
geometry of the junction. Inhomogenity of stress distribution at the
interface of junction of two materials with different elastic modules
and stress concentration in this zone are the main factors resulting in
rupture of the junction. Effect of joining angle in the interface of
aluminum-polycarbonate will be discussed in this paper. Computer
simulation and finite element analysis by ABAQUS showed that
convex interfacial joint leads to stress reduction at junction corners in
compare with straight joint. This finding is confirmed by photoelastic
experimental results.
Abstract: This paper proposes transient angle stability
agents to enhance power system stability. The proposed transient
angle stability agents divided into two strategy agents. The
first strategy agent is a prediction agent that will predict power
system instability. According to the prediction agent-s output,
the second strategy agent, which is a control agent, is automatically
calculating the amount of active power reduction that can
stabilize the system and initiating a control action. The control
action considered is turbine fast valving. The proposed strategies
are applied to a realistic power system, the IEEE 50-
generator system. Results show that the proposed technique can
be used on-line for power system instability prediction and control.
Abstract: The design of a steam turbine is a very complex
engineering operation that can be simplified and improved thanks to
computer-aided multi-objective optimization. This process makes use
of existing optimization algorithms and losses correlations to identify
those geometries that deliver the best balance of performance (i.e.
Pareto-optimal points).
This paper deals with a one-dimensional multi-objective and
multi-point optimization of a single-stage steam turbine. Using a
genetic optimization algorithm and an algebraic one-dimensional
ideal gas-path model based on loss and deviation correlations, a code
capable of performing the optimization of a predefined steam turbine
stage was developed. More specifically, during this study the
parameters modified (i.e. decision variables) to identify the best
performing geometries were solidity and angles both for stator and
rotor cascades, while the objective functions to maximize were totalto-
static efficiency and specific work done.
Finally, an accurate analysis of the obtained results was carried
out.
Abstract: The Beshar River is one aquatic ecosystem,which is
affected by pollutants. This study was conducted to evaluate the
effects of human activities on the water quality of the Beshar river.
This river is approximately 190 km in length and situated at the
geographical positions of 51° 20' to 51° 48' E and 30° 18' to 30° 52'
N it is one of the most important aquatic ecosystems of Kohkiloye
and Boyerahmad province next to the city of Yasuj in southern Iran.
The Beshar river has been contaminated by industrial, agricultural
and other activities in this region such as factories, hospitals,
agricultural farms, urban surface runoff and effluent of wastewater
treatment plants. In order to evaluate the effects of these pollutants
on the quality of the Beshar river, five monitoring stations were
selected along its course. The first station is located upstream of
Yasuj near the Dehnow village; stations 2 to 4 are located east, south
and west of city; and the 5th station is located downstream of Yasuj.
Several water quality parameters were sampled. These include pH,
dissolved oxygen, biological oxygen demand (BOD), temperature,
conductivity, turbidity, total dissolved solids and discharge or flow
measurements. Water samples from the five stations were collected
and analysed to determine the following physicochemical
parameters: EC, pH, T.D.S, T.H, No2, DO, BOD5, COD during 2008
to 2009. The study shows that the BOD5 value of station 1 is at a
minimum (1.5 ppm) and increases downstream from stations 2 to 4 to
a maximum (7.2 ppm), and then decreases at station 5. The DO
values of station 1 is a maximum (9.55 ppm), decreases downstream
to stations 2 - 4 which are at a minimum (3.4 ppm), before increasing
at station 5. The amount of BOD and TDS are highest at the 4th
station and the amount of DO is lowest at this station, marking the
4th station as more highly polluted than the other stations. The
physicochemical parameters improve at the 5th station due to
pollutant degradation and dilution. Finally the point and nonpoint
pollutant sources of Beshar river were determined and compared to
the monitoring results.
Abstract: It is hard to percept the interaction process with machines when visual information is not available. In this paper, we have addressed this issue to provide interaction through visual techniques. Posture recognition is done for American Sign Language to recognize static alphabets and numbers. 3D information is exploited to obtain segmentation of hands and face using normal Gaussian distribution and depth information. Features for posture recognition are computed using statistical and geometrical properties which are translation, rotation and scale invariant. Hu-Moment as statistical features and; circularity and rectangularity as geometrical features are incorporated to build the feature vectors. These feature vectors are used to train SVM for classification that recognizes static alphabets and numbers. For the alphabets, curvature analysis is carried out to reduce the misclassifications. The experimental results show that proposed system recognizes posture symbols by achieving recognition rate of 98.65% and 98.6% for ASL alphabets and numbers respectively.
Abstract: Using finite element method (FEM), the elastic
new strain-concentration factor (SNCF) of cylindrical bars
with circumferential flat-bottom groove is studied. This new
SNCF has been defined under triaxial stress state. The
employed specimens have constant groove depth with net
section and gross diameters of 10.0 and 16.7 mm,
respectively. The length of flatness ao has been varied form
0.0 ~12.5 mm to study the elastic SNCF of this type of
geometrical irregularities. The results that the elastic new
SNCF rapidly drops from its elastic value of the groove with
ao = 0.0, i.e. circumferential U-notch, and reaches minimum
value at ao = 2 mm. After that the elastic new SNCF becomes
nearly constant with increasing flatness length (ao). The value
of tensile load at yielding at the groove root increases with
increasing ao. The current results show that severity of the
notch decreases with increasing flatness length ao.
Abstract: In this manuscript, a wavelet-based blind
watermarking scheme has been proposed as a means to provide
security to authenticity of a fingerprint. The information used for
identification or verification of a fingerprint mainly lies in its
minutiae. By robust watermarking of the minutiae in the fingerprint
image itself, the useful information can be extracted accurately even
if the fingerprint is severely degraded. The minutiae are converted in
a binary watermark and embedding these watermarks in the detail
regions increases the robustness of watermarking, at little to no
additional impact on image quality. It has been experimentally shown
that when the minutiae is embedded into wavelet detail coefficients
of a fingerprint image in spread spectrum fashion using a
pseudorandom sequence, the robustness is observed to have a
proportional response while perceptual invisibility has an inversely
proportional response to amplification factor “K". The DWT-based
technique has been found to be very robust against noises,
geometrical distortions filtering and JPEG compression attacks and is
also found to give remarkably better performance than DCT-based
technique in terms of correlation coefficient and number of erroneous
minutiae.
Abstract: This paper presents nonlinear elastic dynamic analysis
of 3-D semi-rigid steel frames including geometric and connection
nonlinearities. The geometric nonlinearity is considered by using
stability functions and updating geometric stiffness matrix. The
nonlinear behavior of the steel beam-to-column connection is
considered by using a zero-length independent connection element
comprising of six translational and rotational springs. The nonlinear
dynamic equilibrium equations are solved by the Newmark numerical
integration method. The nonlinear time-history analysis results are
compared with those of previous studies and commercial SAP2000
software to verify the accuracy and efficiency of the proposed
procedure.
Abstract: The present paper reports the removal of Cd(II) and
Zn(II) ions using synthetic Zeolit NaA. The adsorption capacity of
the sorbent (Zeolite NaA) strongly depends on simultaneous or not
simultaneous (concurrent) presence of Cd(II) and Zn(II) in the
sorbate. When Cd(II) and Zn(II) are present simultaneously
(concurrently) in the sorbate, Zn(II) ions were sorbed at higher rate.
Equilibrium data fitted Langmuir, Freundlich and Tempkin isotherms
well. The applicability of the isotherm equation to describe the
adsorption process was judged by the correlation coefficients R2. The
Langmuir model yielded the best fit with R2 values equal to or higher
than 0.970, as compared to the Freundlich and Tempkin models. The
fact that 1/n values range from 0.322 to 0.755 indicates that the
adsorption of Cd(II) and Zn(II) ions from aqueous solutions also
favored by the Freundlich model.
Abstract: Physical and mechanical properties of Russian olive
fruits were measured at moisture content of 14.43% w.b. The results
revealed that the mean length, width and thickness of Russian olive
fruits were 20.72, 15.73 and 14.69mm, respectively. Mean mass and
volume of Russian olive fruits were measured as 1.45 g and 2.55 cm3,
respectively. The sphericity, aspect ratio and surface area were
calculated as 0.81, 0.72 and 8.96 cm2, respectively, while arithmetic
mean diameter, geometric mean diameter and equivalent diameter of
Russian olive fruits were 17.05, 16.83 and 16.84 mm, respectively.
Whole fruit density, bulk density and porosity of jujube fruits were
measured and found to be 1.01 g/cm3, 0.29 g/cm3 and 69.5%,
respectively. The values of static coefficient of friction on three
surfaces of glass, galvanized iron and plywood were 0.35, 0.36 and
0.43, respectively. The skin color (L*, a*, b*) varied from 9.92 to
16.08; 2.04 to 3.91 and 1.12 to 3.83, respectively. The values of
rupture force, deformation, energy absorbed and hardness were found
to be between 12.14-16.85 N, 2.16-4.25 mm, 3.42-6.99 N mm and
17.1-23.85 N/mm.
Abstract: Wireless Sensor Networks (WSNs) are used to monitor/observe vast inaccessible regions through deployment of large number of sensor nodes in the sensing area. For majority of WSN applications, the collected data needs to be combined with geographic information of its origin to make it useful for the user; information received from remote Sensor Nodes (SNs) that are several hops away from base station/sink is meaningless without knowledge of its source. In addition to this, location information of SNs can also be used to propose/develop new network protocols for WSNs to improve their energy efficiency and lifetime. In this paper, range free localization protocols for WSNs have been proposed. The proposed protocols are based on weighted centroid localization technique, where the edge weights of SNs are decided by utilizing fuzzy logic inference for received signal strength and link quality between the nodes. The fuzzification is carried out using (i) Mamdani, (ii) Sugeno, and (iii) Combined Mamdani Sugeno fuzzy logic inference. Simulation results demonstrate that proposed protocols provide better accuracy in node localization compared to conventional centroid based localization protocols despite presence of unintentional radio frequency interference from radio frequency (RF) sources operating in same frequency band.
Abstract: The article deals with the problems of political and
economic processes in Kazakhstan since independence in the context
of globalization. It analyzes the geopolitical situation and selfpositioning
processes in the world after the end of the "cold war". It
examines the problems of internal economization of the Republic for
20 years of independence. The authors argue that the reforms
proceeded in the economic sphere have brought ambiguous and
tangible results. Despite the difficult economic and political conditions
facing a world economical crisis the country has undergone
fundamental and radical transformations in the whole socio-economic
system
Abstract: In this work, several ASP solutions were flooded into
fractured models initially saturated with heavy oil at a constant flow
rate and different geometrical characteristics of fracture. The ASP
solutions are constituted from 2 polymers i.e. a synthetic polymer,
hydrolyzed polyacrylamide as well as a biopolymer, a surfactant and
2types of alkaline. The results showed that using synthetic
hydrolyzed polyacrylamide polymer increases ultimate oil recovery;
however, type of alkaline does not play a significant rule on oil
recovery. In addition, position of the injection well respect to the
fracture system has remarkable effects on ASP flooding. For instance
increasing angle of fractures with mean flow direction causes more
oil recovery and delays breakthrough time. This work can be
accounted as a comprehensive survey on ASP flooding which
considers most of effective factors in this chemical EOR method.
Abstract: This paper is mainly concerned with the application of
a novel technique of data interpretation for classifying measurements
of plasma columns in Tokamak reactors for nuclear fusion
applications. The proposed method exploits several concepts derived
from soft computing theory. In particular, Artificial Neural Networks
and Multi-Class Support Vector Machines have been exploited to
classify magnetic variables useful to determine shape and position of
the plasma with a reduced computational complexity. The proposed
technique is used to analyze simulated databases of plasma equilibria
based on ITER geometry configuration. As well as demonstrating the
successful recovery of scalar equilibrium parameters, we show that
the technique can yield practical advantages compared with earlier
methods.
Abstract: We study the spatial design of experiment and we want to select a most informative subset, having prespecified size, from a set of correlated random variables. The problem arises in many applied domains, such as meteorology, environmental statistics, and statistical geology. In these applications, observations can be collected at different locations and possibly at different times. In spatial design, when the design region and the set of interest are discrete then the covariance matrix completely describe any objective function and our goal is to choose a feasible design that minimizes the resulting uncertainty. The problem is recast as that of maximizing the determinant of the covariance matrix of the chosen subset. This problem is NP-hard. For using these designs in computer experiments, in many cases, the design space is very large and it's not possible to calculate the exact optimal solution. Heuristic optimization methods can discover efficient experiment designs in situations where traditional designs cannot be applied, exchange methods are ineffective and exact solution not possible. We developed a GA algorithm to take advantage of the exploratory power of this algorithm. The successful application of this method is demonstrated in large design space. We consider a real case of design of experiment. In our problem, design space is very large and for solving the problem, we used proposed GA algorithm.