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The chemical-morphological relationships in rainbow trout, Oncorhynchus mykiss, was assessed through photography in light room. The image data were transferred to a laptop and analyzed by MATLAB (Matrix Laboratory) version R2009a. The designated algorithm of 7 features, including length, height, area, perimeter, equivalent diameter, major and minor axis length were extracted from the images. Afterward, chemical compositions of the fish (including crude protein, crude fat, moisture content, pH value and leakage), were determined. Pearson's correlation coefficient was used to correlate visual and chemical properties. Factors were assayed with linear, logarithmic, exponential and power method. Results showed that pH, leakage, protein and fat had a good correlation with fish length, and moisture with fish perimeter, in Quadratic equation (R²= 0.993, 0.991, 0.991, 0.989 and 0.992, respectively). In conclusion, this methodology can be applied for automated chemical analysis and on-line monitoring in fish farms.

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For the first time, this paper analyzes the portfolio selection theory in the presence of housing market in Iran. One of the important theories about the housing price is household portfolio theory. Based on the theory, housing business cycles have determining effect on housing share in portfolio. For this purpose, a set of assets data consisting stocks, exchange, gold coins, bank deposits, bonds and housing over the period 1991-2006 are used. After calculation of returns, risks and correlation coefficients of assets over the period using Mean - Variance Model and MATLAB software, a combination of household assets in the portfolio have been extracted .The model, through simulating and supposing different weights for each asset determines an optimal combination of assets in portfolio based on risk classification of households: low risk, medium risk and high risk. Then, they are thoroughly examined to explore: whether the presence of housing asset in the portfolio can improve its risk, return and the composition of assets? Efficient frontier which covers all portfolios is also extracted. The results reveal that housing is an important asset in the portfolio during the housing boom period and causes the efficient frontier transmission move outwards.

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In this paper, crack detection possibility in an arch dam structure is investigated by wavelet transform analysis. An arch dam is a solid concrete dam, curved upstream in plan. In addition to resisting part of the pressure of the reservoir by its own weight, it obtains a large measure of stability by transmitting the remainder of the water pressure and other loads by arch action into the canyon walls. The complete necessity of high safety, economical design, complex of designing and its application increase the importance of concrete arch dams. Successful arch action is dependent on a unified monolithic structure, and special care must be taken in the construction of an arch dam to ensure that no structural discontinuities such as open joints or cracks exist at the time the structure assumes its water load. According to the principles of theory of structures, there is a relationship between the dynamic and static responses and, consequently, the stiffness. Any sudden change in stiffness leads to dynamic and static response variation. This condition will help to estimate the damage and to investigate the structural response before and after the failure. Wavelet analysis has recently been considered for damage detection and structural health monitoring (SHM). It provides a powerful tool to characterize local features of a signal. The basis function in wavelet analysis is defined by two parameters: scale and translation. This property leads to a multi-resolution representation for stationary signals. It has high ability in analysis of static and dynamic response signals. Staionary wavelet transform (SWT) can show the location of frequency changes. That these locations are the points that they have been damaged. The case study is the concrete curvature arch of KAROON-1 (Shahid Abbaspour) dam with the height of 200 m. This dam is considered as one of the most complex dams because of different external and internal radia and angles, as well as asymmetrical center of the external and internal archs in different levels. Using the geometrical dimensions of the above-mentioned dam- from respective design sheetsand its mechanical and physical properties, the dam with and without crack was modeled by the ABAQUS FE software package. After frequency analysis of the dam by ABAQUS for both safe and cracked models in the same frequency mode, displacement responses at the cracked level (crest) were extracted along the reservoir’s longitudinal axis. Afterwards, the responses were used for the wavelet analysis by the wavelet toolbar of the MATLAB software and the detection of crack in the dam structure was investigated with SWT. The results of wavelet analysis showed that the graphs have considerable rise at or around the crack location. But there was no noise or any harmony in the graphs of the safe dam. Hence, detecting the location of crack in dam structures is possible with wavelet transform.

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In this paper the modeling of combined heat and power (CHP) system driven by Stirling engine has been discussed. The system consists of one beta type Stirling engine as the prime mover, heat recovery system, power generator and the auxiliary boiler. The analysis of the Stirling engine is a non-ideal adiabatic analysis. To increase the accuracy of modeling, the frictional and thermal losses of Stirling engine are considered in comparison of other previous studies and the non-ideal adiabatic analysis is performed using a developed numerical code in MATLAB software. For model validation, the operational and geometrical specification of the GPU-3 Stirling engine was used and the results were compared with experimental results and other previous models. Then, one beta-type Stirling engine was proposed as prime mover in cogeneration system for building applications. The use of the cogeneration systems in building applications becomes more common, which system from the perspective of the fuel consumption and pollution emission, have a significant advantage in comparison with the other conventional systems. For this purpose, the effects of engine frequency, regenerator length, and heat source temperature on fuel consumption and pollution emission of system were examined and proper engine design parameters were selected. Finally, the electric power and thermal power were achieved 11263 W and 21653 W, respectively, with reduction in fuel consumption and pollution emission of 37% and 42%, respectively.

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In this paper, a commercial metal-oxide gas sensor was first placed under temperature modulation regime and simultaneously their transient response to various concentrations of ethanol vapors was recorded. By applying the temperature modulation, the sensor surface temperature was also recorded by a S-type thermocouple. Then, the performance of these sensors was expressed based on the both air oxygen absorption model and ethanol absorption on the surface of the sensitive layer using the Freundlich isotherm equation. Further, this model is simulated using the MATLAB software in the simulink environment. Using this model, one can see the sensor's dynamic response to ethanol. In this model, the concentration of a gas is considered as a voltage. This parameter, along with the temperature profile of the sensor surface under temperature modulation and sensor conductance under the influence of air oxygen, are considered as inputs of the model and transient response of the sensor as output of the model. The parameters of this model are calculated based on the approximate criterion of simulated responses and the responses recorded for each concentration of ethanol gas. The simulation results based on the average simulated parameters also showed that the simulated responses were close to the actual recorded responses.

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In this research, micro-nano bubbles formation inside the venturi tube has been investigated using image processing technique and high-speed photography. For the purpose, two models of venturi tubes with different dimensions were made of light and transparent plexiglass and then they were tested with various water flow discharges. After the injection of air into the venturi tube, a high-speed camera has been used to capture images of two-phase flows passing through the venturi tube. The captured images were processed by MATLAB software. After investigating the results and obtaining the average diameter of the bubbles, the number of Micro-Nano bubbles and the velocity in the center of venturi tube have been calculated and the related graphs have been analyzed. The results show that reducing bottleneck length and increasing flow discharge inside the venturi tube lead to the formation of smaller bubbles and the number of Micro-Nano bubble increases.