Abstract: In this paper, an analytical approach for free vibration
analysis of rectangular and circular membranes 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 rectangular and circular membranes are
derived. Then, these matrices are combined to provide a concise and
systematic approach to free vibration analysis of membranes.
Subsequently, the eigenvalue problem for free vibration of membrane
is formulated and the equation of membrane natural frequencies is
constructed. Finally, the effectiveness of the approach is shown by
comparison of the results with existing classical solution.
Abstract: The objective of the present study was to examine the
dose-response relationships between antioxidant parameters and liver
contaminant levels of Kazakhstan light crude oil (KLCO) in albino
rats. The animals were repeatedly exposed, by intraperitoneal
injection, to low dosages (0.5–1.5 ml/kg) of KLCO. Rats exposed to
these doses levels did not show any apparent symptoms of
intoxication. Serum aminotransferases increased significantly
(p
Abstract: In this paper we evaluated the efficacy of
photodynamic treatment of infected wounds on pig animal model by
diffuse reflectance spectrometry. The study was conducted on fifteen
wounds contaminated with Staphylococcus aureus bacteria that were
incubated for 30 min with methylene blue solution (c = 3.3 x 10-3 M)
and exposed to laser radiations (λ = 670 nm, P = 15 mW) for 15 min.
The efficiency of photodynamic inactivation of bacteria was
evaluated by microbiological exams and diffuse reflectance
spectrometry. The results of the microbiological exams showed that
the bacterial concentration has decreased from 6.93±0.138
logCFU/ml to 3.12±0.108 logCFU/ml. The spectral examination
showed that the diffuse reflectance of wounds contaminated with
Staphylococcus aureus has decreased from 5.06±0.036 % to
3.36±0.025 %. In conclusion, photodynamic therapy is an effective
method for the treatment of infected wounds and there is a correlation
between the CFU count and diffuse reflectance.
Abstract: The aim of the work presented here was to either use
existing forest dynamic simulation models or calibrate a new one
both within the SYMFOR framework with the purpose of examining
changes in stand level basal area and functional composition in
response to selective logging considering trees > 10 cm d.b.h for two
areas of undisturbed Amazonian non flooded tropical forest in Brazil
and one in Peru. Model biological realism was evaluated for forest in
the undisturbed and selectively logged state and it was concluded that
forest dynamics were realistically represented. Results of the logging
simulation experiments showed that in relation to undisturbed forest
simulation subject to no form of harvesting intervention there was a
significant amount of change over a 90 year simulation period that
was positively proportional to the intensity of logging. Areas which
had in the dynamic equilibrium of undisturbed forest a greater
proportion of a specific ecological guild of trees known as the light
hardwoods (LHW’s) seemed to respond more favorably in terms of
less deviation but only within a specific range of baseline forest
composition beyond which compositional diversity became more
important. These finds are in line partially with practical management
experience and partiality basic systematics theory respectively.
Abstract: In this study, the dispersion of heavy particles line in
an isotropic and incompressible three-dimensional turbulent flow has
been studied using the Kinematic Simulation techniques to find out
the evolution of the line fractal dimension. The fractal dimension of
the line is found in the case of different particle gravity (in practice,
different values of particle drift velocity) in the presence of small
particle inertia with a comparison with that obtained in the diffusion
case of material line at the same Reynolds number. It can be
concluded for the dispersion of heavy particles line in turbulent flow
that the particle gravity affect the fractal dimension of the line for
different particle gravity velocities in the range 0.2 < W < 2. With
the increase of the particle drift velocity, the fractal dimension of the
line decreases which may be explained as the particles pass many
scales in their journey in the direction of the gravity and the particles
trajectories do not affect by these scales at high particle drift
velocities.
Abstract: An effective approach for realizing the binary tree structure, representing a combinational logic functionality with enhanced throughput, is discussed in this paper. The optimization in maximum operating frequency was achieved through delay minimization, which in turn was possible by means of reducing the depth of the binary network. The proposed synthesis methodology has been validated by experimentation with FPGA as the target technology. Though our proposal is technology independent, yet the heuristic enables better optimization in throughput even after technology mapping for such Boolean functionality; whose reduced CNF form is associated with a lesser literal cost than its reduced DNF form at the Boolean equation level. For cases otherwise, our method converges to similar results as that of [12]. The practical results obtained for a variety of case studies demonstrate an improvement in the maximum throughput rate for Spartan IIE (XC2S50E-7FT256) and Spartan 3 (XC3S50-4PQ144) FPGA logic families by 10.49% and 13.68% respectively. With respect to the LUTs and IOBUFs required for physical implementation of the requisite non-regenerative logic functionality, the proposed method enabled savings to the tune of 44.35% and 44.67% respectively, over the existing efficient method available in literature [12].
Abstract: Using a force balanced translational-radial dynamics,
phase space of the moving single bubble sonoluminescence (m-
SBSL) in 85% wt sulfuric acid has been numerically calculated. This
phase space is compared with that of single bubble sonoluminescence
(SBSL) in pure water which has been calculated by using the mere
radial dynamics. It is shown that in 85% wt sulfuric acid, in a general
agreement with experiment, the bubble-s positional instability
threshold lays under the shape instability threshold. At the onset of
spatial instability of moving sonoluminescing (SL) bubble in 85%
wt sulfuric acid, temporal effects of the hydrodynamic force on the
bubble translational-radial dynamics have been investigated. The
appearance of non-zero history force on the moving SL bubble is
because of proper condition which was produced by high viscosity of
acid. Around the moving bubble collapse due to the rapid contraction
of the bubble wall, the inertial based added mass force overcomes the
viscous based history force and induces acceleration on the bubble
translational motion.
Abstract: Subcritical water extraction was investigated as a
novel and alternative technology in the food and pharmaceutical
industry for the separation of Mannitol from olive leaves and its
results was compared with those of Soxhlet extraction. The effects of
temperature, pressure, and flow rate of water and also momentum
and mass transfer dimensionless variables such as Reynolds and
Peclet Numbers on extraction yield and equilibrium partition
coefficient were investigated. The 30-110 bars, 60-150°C, and flow
rates of 0.2-2 mL/min were the water operating conditions. The
results revealed that the highest Mannitol yield was obtained at
100°C and 50 bars. However, extraction of Mannitol was not
influenced by the variations of flow rate. The mathematical modeling
of experimental measurements was also investigated and the model is
capable of predicting the experimental measurements very well. In
addition, the results indicated higher extraction yield for the
subcritical water extraction in contrast to Soxhlet method.
Abstract: This study was conducted to investigate the efficacy
of five herbicides on narrow leaved weeds and growth and yield of
wheat. An experiment was conducted at Agronomic Research
Farm, University of Agriculture Faisalabad. The experiment was
laid out in randomized complete block designee (RCBD) with three
replications. Treatments studied were clodinafop (Topic-15 WG) at
37 g a.i. ha-1, clodinafop (Topaz-15 WG) at 45 g a.i. ha-1,
fenoxaprop-p-ethyl (Puma Super-75 EW) at 45 g a.i. ha-1,
fenoxaprop-p-ethyl (Gramicide-6.9 EW) at 85 g a.i. ha-1,
fenoxaprop-p-ethyl (Chinlima-6.9 EW) at 85 g a.i. ha-1 and weedy
check. Plots treated with fenoxaprop-p-ethyl (Puma Super-75 EW)
at 45 g a.i. ha-1 produced relatively less weed biomass, more plant
height, number of spike bearing tillers, number of grains per spike,
1000-grain weight and grain yield (4.20 t ha-1).
Abstract: In inspection and workpiece localization, sampling point data is an important issue. Since the devices for sampling only sample discrete points, not the completely surface, sampling size and location of the points will be taken into consideration. In this paper a method is presented for determining the sampled points size and location for achieving efficient sampling. Firstly, uncertainty analysis of the localization parameters is investigated. A localization uncertainty model is developed to predict the uncertainty of the localization process. Using this model the minimum size of the sampled points is predicted. Secondly, based on the algebra theory an eigenvalue-optimal optimization is proposed. Then a freeform surface is used in the simulation. The proposed optimization is implemented. The simulation result shows its effectivity.
Abstract: The main objective of this study was to determine if a
minimal increase in road light level (luminance) could lead to
improved driving performance among older adults. Older, middleaged
and younger adults were tested in a driving simulator following
vision and cognitive screening. Comparisons were made for the
performance of simulated night driving under two road light
conditions (0.6 and 2.5 cd/m2). At each light level, the effects of self
reported night driving avoidance were examined along with the
vision/cognitive performance. It was found that increasing road light
level from 0.6 cd/m2 to 2.5 cd/m2 resulted in improved recognition of
signage on straight highway segments. The improvement depends on
different driver-related factors such as vision and cognitive abilities,
and confidence. On curved road sections, the results showed that
driver-s performance worsened. It is concluded that while increasing
road lighting may be helpful to older adults especially for sign
recognition, it may also result in increased driving confidence and
thus reduced attention in some driving situations.
Abstract: This paper provides an exergy analysis of the multistage refrigeration cycle used for C2+ recovery plant. The behavior of an industrial refrigeration cycle with refrigerant propane has been investigated by the exergy method. A computational model based on the exergy analysis is presented for the investigation of the effects of the valves on the exergy losses, the second law of efficiency, and the coefficient of performance (COP) of a vapor compression refrigeration cycle. The equations of exergy destruction and exergetic efficiency for the main cycle components such as evaporators, condensers, compressors, and expansion valves are developed. The relations for the total exergy destruction in the cycle and the cycle exergetic efficiency are obtained. An ethane recovery unit with its refrigeration cycle has been simulated to prepare the exergy analysis. Using a typical actual work input value; the exergetic efficiency of the refrigeration cycle is determined to be 39.90% indicating a great potential for improvements. The simulation results reveal that the exergetic efficiencies of the heat exchanger and expansion sections get the lowest rank among the other compartments of refrigeration cycle. Refrigeration calculations have been carried out through the analysis of T–S and P–H diagrams where coefficient of performance (COP) was obtained as 1.85. The novelty of this article includes the effect and sensitivity analysis of molar flow, pressure drops and temperature on the exergy efficiency and coefficient of performance of the cycle.
Abstract: We present a general comparison of punctual kriging based image restoration for different neighbourhood sizes. The formulation of the technique under consideration is based on punctual kriging and fuzzy concepts for image restoration in spatial domain. Three different neighbourhood windows are considered to estimate the semivariance at different lags for studying its effect in reduction of negative weights resulted in punctual kriging, consequently restoration of degraded images. Our results show that effect of neighbourhood size higher than 5x5 on reduction in negative weights is insignificant. In addition, image quality measures, such as structure similarity indices, peak signal to noise ratios and the new variogram based quality measures; show that 3x3 window size gives better performance as compared with larger window sizes.
Abstract: With the presence of a uniform vertical magnetic field and suspended particles, thermocapillary instability in a horizontal liquid layer is investigated. The resulting eigenvalue is solved by the Galerkin technique for various basic temperature gradients. It is found that the presence of magnetic field always has a stability effect of increasing the critical Marangoni number.
Abstract: A complex valued neural network is a neural network, which consists of complex valued input and/or weights and/or thresholds and/or activation functions. Complex-valued neural networks have been widening the scope of applications not only in electronics and informatics, but also in social systems. One of the most important applications of the complex valued neural network is in image and vision processing. In Neural networks, radial basis functions are often used for interpolation in multidimensional space. A Radial Basis function is a function, which has built into it a distance criterion with respect to a centre. Radial basis functions have often been applied in the area of neural networks where they may be used as a replacement for the sigmoid hidden layer transfer characteristic in multi-layer perceptron. This paper aims to present exhaustive results of using RBF units in a complex-valued neural network model that uses the back-propagation algorithm (called 'Complex-BP') for learning. Our experiments results demonstrate the effectiveness of a Radial basis function in a complex valued neural network in image recognition over a real valued neural network. We have studied and stated various observations like effect of learning rates, ranges of the initial weights randomly selected, error functions used and number of iterations for the convergence of error on a neural network model with RBF units. Some inherent properties of this complex back propagation algorithm are also studied and discussed.
Abstract: Molodstov-s soft sets theory was originally proposed
as general mathematical tool for dealing with uncertainty problems. The matrix form has been introduced in soft set and some of its
properties have been discussed. However, the formulation of soft
matrix in group decision making problem only with equal importance
weights of criteria, which does not show the true opinion of decision maker on each criteria. The aim of this paper is to propose a method
for solving group decision making problem incorporating the importance of criteria by using soft matrices in a more objective manner. The weight of each criterion is calculated by using the Analytic Hierarchy Process (AHP) method. An example of house
selection process is given to illustrate the effectiveness of the proposed method.
Abstract: Polyurethanes (PURs) are very versatile polymeric
materials with a wide range of physical and chemical properties.
PURs have desirable properties such as high abrasion resistance, tear
strength, shock absorption, flexibility and elasticity. Although they
have relatively poor thermal stability, this can be improved by using
treated clay. Polyurethane/clay nanocomposites have been
synthesized from renewable sources. A polyol for the production of
polyurethane by reaction with an isocyanate was obtained by the
synthesis of palm oil-based oleic acid with glycerol. Dodecylbenzene
sulfonic acid (DBSA) was used as catalyst and emulsifier. The
unmodified clay (kunipia-F) was treated with cetyltrimethyl
ammonium bromide (CTAB-mont) and octadodecylamine (ODAmont).
The d-spacing in CTAB-mont and ODA-mont were 1.571 nm
and 1.798 nm respectively and larger than that of the pure-mont
(1.142 nm). The organoclay was completely intercalated in the
polyurethane, as confirmed by a wide angle x-ray diffraction
(WAXD) pattern.
The results showed that adding clay demonstrated better thermal
stability in comparison with the virgin polyurethane. Onset
degradation of pure PU is at 200oC, and is lower than that of the
CTAB-mont PU and ODA-mont PU which takes place at about
318oC and 330oC, respectively. The mechanical properties (including
the dynamic mechanical properties) of pure polyurethane (PU) and
PU/clay nanocomposites, were measured. The modified organoclay
had a remarkably beneficial effect on the strength and elongation at
break of the nanocomposites, which both increased with increasing
clay content with the increase of the tensile strength of more than
214% and 267% by the addition of only 5 wt% of the
montmorillonite CTAB-mont PU and ODA-mont PU, respectively.
Abstract: Genetic algorithms (GAs) have been widely used for
global optimization problems. The GA performance depends highly
on the choice of the search space for each parameter to be optimized.
Often, this choice is a problem-based experience. The search space
being a set of potential solutions may contain the global optimum
and/or other local optimums. A bad choice of this search space
results in poor solutions. In this paper, our approach consists in
extending the search space boundaries during the GA optimization,
only when it is required. This leads to more diversification of GA
population by new solutions that were not available with fixed search
space boundaries. So, these dynamic search spaces can improve the
GA optimization performances. The proposed approach is applied to
power system stabilizer optimization for multimachine power system
(16-generator and 68-bus). The obtained results are evaluated and
compared with those obtained by ordinary GAs. Eigenvalue analysis
and nonlinear system simulation results show the effectiveness of the
proposed approach to damp out the electromechanical oscillation and
enhance the global system stability.
Abstract: Industrial surveys shows that manufacturing
companies define the qualities of thermal removing process based on
the dimension and physical appearance of the cutting material
surface. Therefore, the roughness of the surface area of the material
cut by the plasma arc cutting process and the rate of the removed
material by the manual plasma arc cutting machine was importantly
considered. Plasma arc cutter Selco Genesis 90 was used to cut
Standard AISI 1017 Steel of 200 mm x100 mm x 6 mm manually
based on the selected parameters setting. The material removal rate
(MRR) was measured by determining the weight of the specimens
before and after the cutting process. The surface roughness (SR)
analysis was conducted using Mitutoyo CS-3100 to determine the
average roughness value (Ra). Taguchi method was utilized to
achieve optimum condition for both outputs studied. The
microstructure analysis in the region of the cutting surface is
performed using SEM. The results reveal that the SR values are
inversely proportional to the MRR values. The quality of the surface
roughness depends on the dross peak that occurred after the cutting
process.
Abstract: Dual bell nozzle is a promising one among the altitude
adaptation nozzle concepts, which offer increased nozzle
performance in rocket engines. Its advantage is the simplicity it offers
due to the absence of any additional mechanical device or movable
parts. Hence it offers reliability along with improved nozzle
performance as demanded by future launch vehicles. Among other
issues, the flow transition to the extension nozzle of a dual bell
nozzle is one of the major issues being studied in the development of
dual bell nozzle. A parameter named over-expansion factor, which
controls the value of the wall inflection angle, has been reported to
have substantial influence in this transition process. This paper
studies, through CFD and cold flow experiments, the effect of overexpansion
factor on flow transition in dual bell nozzles.