Synthetic colors are additives which can affect the health and safety of food directly. As a result of the increase of synthetic dyes usage in industry and harmful effects of excessive consumption of synthetic colors on human health, we have attempted to propose a valid method by the simplest laboratory equipment for control dose of synthetic colors in foods. In this study, we have selected ice products as the real sample because of its simple matrix. Here, we have attempted to the determination of all allowed synthetic colors in ice samples as individual and mixtures of them (yellow-red, yellow-blue and red-blue) in one run simultaneously. All validation parameters of the method were calculated for each color and compared with international standards. Obtained results are in accordance with international standards and confirm that this method has a good potential to apply as a valid laboratory method not only for qualitative but also the measurement of synthetic colors in food.

In this study, the method of releasing strains for calculating residual stresses in hole drilling process has been considered. For this purpose, a thick piece of cylindrical aluminum of 5 mm thickness has been investigated. Stepwise and high-speed drilling was performed in several successive steps, and released strains were recorded by a rosette strain gauge. The distribution of released strains in 3 forms of functions in the depth of the hole has been studied to transform strains to stresses, a linear function, a second-order function, and a third-order function. For each case, the longitudinal, tangential, shear stresses, principle stresses, and principle angles in the thickness of the piece were calculated and the results of the convergence analysis by the Tikhonov regularization were evaluated. In the end, the results are evaluated and compared for 3 modes. The results of the comparison of stresses and the degree of curves have shown that the third-order curve is more suitable for evaluation of released strains and using to transform them to residual stresses, and the magnitude of the error in the second-order curve is greater than the two other modes.

An alarm threshold plays an important role in an industrial fault detection system and directly contributes the False Alarm Rate (FAR) and Missed Alarm Rate (MAR). A crucial consideration for designing a threshold is estimating the Probability Density Function (PDF) of both normal and abnormal based on samples. The existence of measurement error in samples will be the contributors to an inaccurate estimation, following that, the alarm threshold will also be inaccurate. Therefore, grasping and recognizing measurement errors is highly important; in this paper, this problem will be investigated. For this purpose, firstly, a mathematical closed-form of statistical parameters will be estimated, and, then, based on error propagation rule, the computation error estimated parameters will be explored. It is assumed the high limit and low limit values of the measurement error are known or computable. Secondly, an approach is introduced to design a varying alarm threshold adapting to the current value of measurement based on . The proposed method is confirmed via a Monte Carlo simulation and it is finally applied to an industrial benchmark, Gas Turbine V94.2, experiencing fouling fault.

In two-dimensional measurements using hot wire anemometer, the sensitivity of the sensor to change the flow direction of direction or of of particular importance. flow velocity vector and heat transfer from the hot wire sensor is determined, using the Yaw sensitivity function and its coefficient. In some cases, negative values of Yaw sensitivity coefficient  are encountered, for which no specific reason has been presented. In this paper, reason of negative values of  for un-plated sensors of hot wire anemometer in two-dimensional measurements have been investigated experimentally. For this purpose, flow velocity field between the prongs of a model of a normal probe (SN) at different velocities and Yaw angles have been studied. Results show that the probe’s prongs produce flow disturbances, which cause a reduction in flow velocity and the deviation (rotation) of the flow adjacent to the prongs and the sensor. At different Yaw angles, the maximum reduction in flow velocity amounts to 3% and the deviation of flow direction has a maximum of 6.3°. It is supposed that this phenomenon affects the amount of heat transfer from the sensor and the effective velocity obtained by the hot wire anemometer, which eventually produces the reported negative  values.

This paper investigates a kind of KNTU1 non-diaphragm shock tube equipped with an innovative design valve within a driven tube. The shock tube is capable of generating a flat shock wave in its driven tube with a length to diameter ratio of 41/6. The KNTU1 shock tube is -type and some limitations of this kind of shock tube such as the lack of without disassembling, the inability to adjust pressure ratio at a specified interval, and the inability to automate the shock tube caused a development on an automated shock tube. In this study, an innovative mechanism to achieve high-speed opening valve with an opening time of 8ms and 10ms is proposed. The unique feature of this automatic valve, compared with existing valves, is its opening from the center to the sides, such as the camera aperture. This is the best way to open the valve and smooth the wave and compensates for a part of the opening time of the valve. Also, the alignment of the driver and the drain prevents disturbances caused by the redirection or rotation of the gas seen in most valves. These help optimize the shock tube. Another initiative in this paper is the design and construction of an optical system to measure the speed and the moment of shock wave arrival to check the shape surface of the shock wave. This system has the ability to move in driven. This paper has been compiled to compare theoretical and experimental data of shock wave.
 

In this paper, the effect of different sensors on the observer performance of vehicle suspension system is investigated. For this purpose, the concept of observable degree analysis is used to quantitatively measure the observability for different sensor choices. A new method, for determining the observable degree of linear time invariant (LTI) systems has been developed on the basis of distance of system from set of similar unobservable systems. A long distance is equivalent to a strong observability and a short distance is equivalent to a weak observability. The zero distance means that the system is unobservable. Since the distance to different unobservable modes can be determined separately, a comprehensive investigation of system observability and the effect of different sensor choices on the observer performance can be provided. In the following, the observable analysis of the suspension system was performed based on the proposed method and the effect of different outputs on the observer performance has been investigated. The results show that when the observable degree is increased for a specific sensor, the observer gain is decreased and consequently the sensitivity of observer relative to the noise and measurement errors is decreased. The increased accuracy of observer demonstrates a good conformity between observable degree analysis and observer performance. Also, a comparative study showed that, contrary to previous criteria that only considered a certain aspect of observability, the proposed method is more comprehensive and realistic, and the results obtained from the previous criteria can easily be achieved through the proposed method.
 

This study aims to investigate the ability of ultrasonic method by using critically refracted longitudinal (L_CR) wave for measuring stress in the elastic phase of an iron-base alloy and a an equation includes of  acoustoelastic constant was provided. For this purpose, extract detail of metal alloy components was achieved by use of quantometer analysis testing and . In order to send and receive the L_CR wave into the samples, the investigation leads to design a unique type of ultrasonic fixture. The fixture was made based on Snell’s law that only in one part. In the next step, different amounts of stress were applied to the specimens by using a uniaxial tensile testing machine and record stress-strain curve data. To this end, more than three metal samples were used in the study. Measurement of longitudinal applied stress by ultrasonic method was done by using 2MHz probes based on Acoustoelasticity theory and close to the surface of the samples. After conducting the experimental tests, the results indicated that there was a significant relation between stress and time of flight and wave speed in the elastic phase of the used sample. Every material has a unique acoustoelastic constant that can determine stress value by having times of flight wave. The conclusions of the study provide a gradient of a line that known as an acoustoelastic constant. Finally, by comparing the results of the used method with other researchers results, findings showed that there were good agreements between them which shows the good capability of acoustoelasticity theory in the measurement of stress.

In order to estimate the amount of flood damage, knowledge of flow characteristics such as speed and flow rate is very important. Nowadays, the use of large-scale particle image velocimetry method is used to estimate flow parameters and flow field in laboratory and field scale. But image processing in relation to important environmental parameters has not been well investigated. To be more precise, the effect of environmental parameters such as; The position of the camera, the speed coefficient, and the sensitivity of the probe window have not been measured. The basis of this research is based on image processing methods, through which flow rate and flow field are calculated. In this study, the capabilities of this method have been accurately measured on a laboratory scale in relation to effective environmental parameters. In this regard, the investigation window of this study shows that the window of 20 pixels provides better results in different depths. In relation to the position of the camera, the studies showed that the placement of the camera obliquely provides the desired results. Regarding the speed coefficient, the studies show that the coefficient between 0.85 and 0.9 provides the best results. The results of the research in laboratory conditions based on the depths of 12.5, 15.5 and 18.5 cm indicate that by using the large-scale particle surface velocimeter system, according to the selection of the optimal conditions, the selection of the appropriate computing network ; camera position; Selection of the search window optimization; hydraulic specifications as well as the appropriate selection of the speed coefficient; It estimates the values of flow rate and flow speed with optimal accuracy. The relative error values of discharge and flow velocity in this research based on the LSPIV method for depths of 12.5, 15.5 and 18.5 cm are equal to 6.5,3.1 and 2.1 percent.